Endocrine Surgery MCQ.docx

8/16/2019 Endocrine Surgery MCQ.docx

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Endocrine Surgery MCQ1. When progressive enlargement of a multinodular goiter causes

symptomatic tracheal compression, the preferred management in otherwise

good-ris patients is!

". #odine treatment.

$. %hyroid hormone treatment.

C. Surgical resection of the a&normal thyroid.

'. (adioactive iodine treatment.

"nswer! C

'#SC)SS#*+! When a multinodular goiter enlarges enough to cause

symptoms of tracheal compression, surgical treatment is usually reuired if

the patient is considered a reasona&le operative ris. Medical treatment may

&e effective in preventing the initial growth of the goiter &ut is unliely to

cause enough regression to relieve symptoms. (adioactive iodine can

occasionally &e used to cause some regression in patients who are poor

anesthesia riss, &ut this is a temporiing treatment rather than a definitive

one.

. %he most precise diagnostic screening procedure for differentiating &enign

thyroid nodules from malignant ones is!

". %hyroid ultrasonography.

$. %hyroid scintiscan.

C. /ine-needle-aspiration &iopsy 0/+"$.

'. %hyroid hormone suppression.

"nswer! C

'#SC)SS#*+! "nalysis of multiple series in which patients with thyroid

nodules have undergone /+"$ has demonstrated a false-negative rate of


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.23 and a false-positive rate of 4.43. Sensitivity for this method is 536

specificity 723. %his surpasses the other methods for accurate selection of

patients who reuire surgical resection.

4. %he preferred operation for initial management of a thyroid nodule that is

considered suspicious for malignancy &y /+"$ is!

". E8cision.

$. 9artial lo&ectomy.

C. %otal lo&ectomy and isthmusectomy.

'. %otal thyroidectomy.

"nswer! C

'#SC)SS#*+! %here is a consensus that the initial minimum operation for a

nodule suspected to &e malignant is total lo&ectomy and isthmusectomy.

9artial lo&ectomy or e8cision of the nodule is associated with a higher ris of

local recurrence if the nodule proves to &e malignant. (eoperation on the side

of a partial lo&ectomy can &e technically difficult and associated with a

higher ris of recurrent nerve in:ury. *rdinarily, total thyroidectomy is not

performed until a conclusive diagnosis of malignancy is esta&lished.

2. "dvantages of total thyroidectomy for management of papillary

carcinomas of the thyroid larger than 1.; cm. include!

". 9ossi&ility of using radioactive iodine postoperatively to identify and treat

metastases.

$. %he a&ility to use thyroglo&ulin levels as a marer for recurrence.

C.


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efficiently &ecause of the a&sence of normal thyroid tissue, which has greater

affinity for iodine than papillary carcinoma tissue. When all normal thyroid

tissue is removed, serum thyroglo&ulin, which is produced &y normal and

malignant thyroid tissue, &ecomes a more effective marer for recurrence.

%he overall recurrence rate is lower for patients undergoing total

thyroidectomy, &ut the ris of hypoparathyroidism is higher for patients who

have total thyroidectomy instead of unilateral lo&ectomy.

;. Which of the following statements a&out follicular carcinoma is=are true>

". #t presents at a later age than papillary carcinoma.

$. #t disseminates via hematogenous routes.C. #t is the most common type of well-differentiated thyroid carcinoma.

'. E8tensive angioinvasion portends a poor prognosis.

E. /ollicular carcinomas are freuently multicentric.

"nswer! "$'

'#SC)SS#*+! /ollicular carcinoma is more common in older patients 0pea

incidence in the fifth decade. %he tumor has a mared propensity for

vascular invasion and spreads hematogenously to &one, lung, liver, andcentral nervous system sites.


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of C-cell hyperplasia in areas of the gland ad:acent to foci of M%C.

'. "ll of the a&ove.

"nswer! '

'#SC)SS#*+! Sporadic M%C is unilateral in at least @A3 of cases.

Bowever, in patients with M%C occurring as a component of the multiple

endocrine neoplasia 0ME+ type " or type $ syndromes, the tumor is

virtually always multifocal and &ilateral. %ypically, in this setting the M%C

appears as multiple whitish-tan tumor nodules in the middle and upper thirds

of each thyroid lo&e.

" diffuse premalignant proliferation of the C cells of the thyroid is thought to

precede the development of M%C in patients with familial M%C. %his proliferation, nown as C-cell hyperplasia 0CCB, consists of parafollicular

clusters of increased num&ers of C cells. %he finding of CCB in areas of the

thyroid ad:acent to gross foci of M%C is strong evidence for familial M%C.

7. "ll of the following are components of the ME+ type $ syndrome

e8cept!

". Multiple neuromas on the lips, tongue, and oral mucosa.$. Byperparathyroidism.

C. M%C.

'. 9heochromocytoma.

"nswer! $

'#SC)SS#*+! M%C and pheochromocytoma occur in &oth ME+ " and

ME+ $ syndromes. 9atients with ME+ " may also develop hyperplasia of

the parathyroid glands. "lthough some investigators have reported euivocal

histologic a&normalities in the parathyroid glands of patients with ME+ $,

hyperparathyroidism is not a component of this syndrome.

#n contrast to patients with ME+ ", those with ME+ $ have a

characteristic phenotype, including a tall, thin marfanoidD ha&itus. 9atients


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with ME+ $ also develop multiple neuromas on the lips, tongue, and oral

mucosa, creating the appearance of thic lips.

@. ME+ " and ME+ $ syndromes are associated with germline mutations

in!

". %he p;4 tumor suppressor gene.

$. %he B-ras gene.

C. %he +-myc gene.

'. %he (E% proto-oncogene.

"nswer! '

'#SC)SS#*+! ermline mutations in the (E% protooncogene, a receptor

tyrosine inase that maps to chromosome 1A, are associated with ME+ "

and ME+ $ syndromes. Bomoygous loss of the tumor suppressor gene p;4

is associated with the


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'#SC)SS#*+! %he pathologic change in the pancreas of patients with ME+

1 is typically multicentric. 'iffuse hyperplasia of islet cells and

microadenoma formation are often identified in areas of the gland distant

from grossly evident tumor. %umors are commonly multifocal. #slet cell

neoplasms of the pancreas occur in 4A3 to @A3 of patients with ME+ 1. %he

most common islet cell neoplasm in these patients is gastrinoma.

astrinomas associated with ME+ 1 pro&a&ly account for A3 to ;A3 of all

cases of the Follinger-Ellison syndrome. %he second most common islet cell

tumor is insulinoma. *ther pancreatic islet cell neoplasms, such as

glucagonoma, somatostatinoma, or vasoactive intestinal polypeptide

neoplasm 0G#9oma, are rarely associated with ME+ 1. "ppro8imately 1A3

of insulinomas and appro8imately 1;3 or more of gastrinomas in patientswith ME+ 1 are malignant.

1A. Which of the following statements a&out the differential diagnosis of

hypercalcemia is=are correct.

". Malignant tumors typically cause hypercalcemia &y ectopic production of

parathyroid hormone 09%B.

$. %he diagnosis of primary hyperparathyroidism is supported &y these serumlevels! calcium, 1A.@ mg. per dl.6 chloride, 1A2 mmol. per liter6 &icar&onate

1 mmol. per liter6 phosphorus, .2 mg. per dl.6 elevated parathyroid

hormone.

C. /amilial hypocalciuric hypercalcemia is distinguished from primary

hyperparathyroidism &y parathyroid imaging.

'. "lthough serum al&umin &inds calcium, the measured total calcium value

is usually unaffected in patients with severe hypoproteinemia.

E. %hiaide diuretics are a good treatment for hypercalcemia and can &e

given to patients with apparent hypercalcemia of malignancy.

"nswer! $

'#SC)SS#*+! Malignant tumors rarely secrete 9%B itself6 they can secrete


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9%Br9 or cytoine activators of osteoclast activity. %he diagnosis of primary

hyperparathyroidism is supported &y hypercalcemia with mild

hyperchloremic meta&olic acidosis and a chloride-phosphate ratio greater

than 44 or a modified chloride 0mmol. per liter=mg. per dl. phosphate ratio

greater than ;AA. /amilial hypocalciuric hypercalcemia is distinguished from

primary hyperparathyroidism &y a low urine calcium. Serum calcium changes

appro8imately A.@ mg. per dl. for every 1 gm. per dl. change in serum

al&umin. %hiaide diuretics can cause hypercalcemia and should not &e given

to patients who are hypercalcemic.

11. #ndications for operation in a patient with previously asymptomatichyperparathyroidism include!

". "ge older than ?A.

$. +ephrolithiasis.

C. " su&stantial decline in renal function.

'. " su&stantial decline in &one mass.

E. 'epression and fatigue.

"nswer! $C'E

'#SC)SS#*+! "ge younger than ;A is considered an indication for

operation.

1. %he parathyroid glands!

". 'evelop from the second and third pharyngeal pouches, along with the

palatine tonsil and the thymus.

$. Migrate caudally in the nec in normal development &ut can &e found

anywhere from the pharyngeal mucosa to the deep mediastinum.

C. Secrete 9%B and calcitonin to manage calcium homeostasis.

'. )sually num&er four, &ut freuently num&er only two or three.

E. Contain enymes that catalye the conversion of ;0*B vitamin ' 4 to


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1,;0*B vitamin ' 4.

"nswer! $

'#SC)SS#*+! %he parathyroid glands develop from the third and fourth

pharyngeal pouches, along with the thymus and the thyroid ultimo&ronchial

&ody6 there are four glands in the vast ma:ority of persons. Calcitonin is

secreted &y the C cells of the thyroid. Gitamin ' 4 hydro8ylation occurs in

the idney.

14. Byperparathyroidism can affect which of the following organs and &ody

systems>". astrointestinal tract.

$. Hidneys.

C. Seleton.

'. +euromuscular system.

E. Cardiovascular system.

"nswer! "$C'E

'#SC)SS#*+! astrointestinal involvement includes pancreatitis and pepticulcer disease. %he idneys can &e affected &y nephrocalcinosis or

nephrolithiasis. %he &ones can &e severely affected &y &one resorption.

+euromuscular complaints can include weaness and fatigue. Bypertension

is present in as many as 7A3 of people with hyperparathyroidism and may &e

related to the renal disease.

12. Secondary hyperparathyroidism!

". #s a meta&olic disease in which the primary a&normality is decreased

glomerular filtration rate.

$. #s &est treated initially &y su&total parathyroidectomy.

C. #s caused &y increased production of 1,;0*B vitamin ' 4, causing


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increasing intestinal calcium a&sorption and hypercalcemia.

'. Can have severe effects on &ones e8acer&ated &y aluminum contained in

phosphate &inders and dialysate water.

E. #s &est treated initially &y total parathyroidectomy with

autotransplantation.

"nswer! "'

'#SC)SS#*+! Secondary hyperparathyroidism is caused &y renal disease,

including decreased glomerular filtration rate and decreased 1,;0*B

vitamin ' 4 production. #t is &est treated &y medical management restricting

dietary phosphate, administering vitamin ' and calcium with phosphate-

&inding gels, and limiting aluminum e8posure, which can e8acer&ate &onedisease.

1;. Bypoparathyroidism!

". #s most commonly encountered as a postviral syndrome.

$. Can &e associated with mared hypocalcemia after parathyroidectomy in

patients with &one disease.

C. Can cause an8iety, depression, or confusion.'. Can cause physical signs such as ChvosteIs and %rousseauIs signs.

E. #s treata&le acutely with intravenous calcium salts and chronically with

oral calcium and vitamin '.

"nswer! $C'E

'#SC)SS#*+! Bypoparathyroidism is most commonly encountered after

thyroid surgery. #t can &e temporarily severe after parathyroidectomy in

patients with &one disease 0postoperative &one hungerD. %he signs and

symptoms can include an8iety, depression, confusion, ChvosteIs sign, and

%rousseauIs sign, as well as circumoral or e8tremity tingling, tetany with

carpopedal spasms, or seiures. %reatment is as noted.


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1?. %rue statements a&out pituitary anatomy and physiology include!

". %he pituitary has dual em&ryonic origin! the anterior pituitary arises from

em&ryonic ectoderm6 the posterior pituitary, from the diencephalon.

$. %he hypophyseal portal system integrates function of the anterior and

posterior pituitary.

C. "drenocorticotropin 0"C%B, formed &y posttranslational processing of

the precursor 9*MC, is normally controlled &y hypothalamic C(/ &ut may

&e released &y immune-related mechanisms.

'. rowth hormone 0B directly stimulates longitudinal growth of the

seleton and growth of muscles.

E. Cell types of the anterior pituitary are classified &y their position in theanterior pituitary and &y their staining characteristics with histologic dyes.

"nswer! "C

'#SC)SS#*+! %he anterior pituitary arises from (atheIs pouch 0em&ryonic

ectoderm, and it includes the pars distalis, pars intermedia, and pars

tu&eralis. %he posterior pituitary arises from the diencephalon and includes

the neural stal, infundi&ulum, and posterior lo&e. %he hypophyseal portal

system drains from the hypothalamus and integrates function of thehypothalamus and anterior pituitary &y carrying hypothalamus-derived

releasing factors to target cells in the anterior pituitary. "C%B may &e

released during stress in response to interleuin-1, -, and -?. Somatotrophic

actions of B are indirect and are mediated &y the insulinlie growth factors

formerly nown as somatomedins. Current classification of anterior pituitary

cells is &ased on immunochemical identification of their secretory products

0i.e., corticotropes produce "C%B, lactotropes produce prolactin, and

thyrotropes produce thyroid-stimulating hormone J%SBK.

17. "ntidiuretic hormone 0"'B!

". #s related to o8ytocin, and &oth are released from the posterior pituitary in


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con:unction with neurophysins.

$. #s released into the circulation &y the posterior pituitary in response to a

rise in plasma osmolality a&ove @; m*sm. or a decrease in circulating &lood

volume.

C. May &e stimulated &y catecholamines and inhi&ited &y phenytoin, alcohol,

and lithium.

'. #n e8cess, may produce a syndrome of euvolemic hyponatremia with

inappropriately concentrated urine that is responsive to free water restriction.

E. 'eficiency causes prolonged polyuria and polydipsia and may &e

diagnosed &y a com&ination of high plasma osmolality and low urine

osmolality following water deprivation.

"nswer! "$C'E

'#SC)SS#*+! "'B and o8ytocin are nineLamino acid peptides derived

from a common ancestral peptide, vasotocin. "'B is released from the

posterior pituitary with neurophysin ## in response to a rise in plasma

osmolality greater than @; m*sm=g. B *. &y a ;3 or greater decrease in

&lood volume, and &y catecholamines. %he syndrome of inappropriate "'B

release 0S#"'B produces euvolemic hyponatremia and is responsive to free

water restriction. 'ia&etes insipidus 0'# reflects a deficiency of "'B andcauses prolonged polyuria and polydipsia. 'ia&etes insipidus is diagnosed &y

a com&ination of high plasma osmolality and low urine osmolality following

water deprivation. E8ogenously administered "'B differentiates central

0"'B-responsive '# from nephrogenic 0"'B-unresponsive '#.

1@. Signs and symptoms of acute pituitary apople8y include!

". Severe headache.

$. Meningismus.

C. Gision loss.

'. Shoc.

E. May &e relieved &y emergent transsphenoidal decompression of the sella


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turcica.

"nswer! "$C'

'#SC)SS#*+! "cute pituitary apople8y follows sudden hemorrhage into a

pre-e8isting pituitary tumor or following closed head trauma. Symptoms,

including headache, meningismus, and vision loss, are attri&uta&le to the

intracere&ral &lood. 9ituitary insufficiency, as well as the accompanying

secondary adrenal insufficiency, may cause hypotension and shoc. *ther

manifestations may include '# and my8edema. "cute pituitary apople8y is a

neurosurgical emergency that reuires transsphenoidal decompression of the

sella turcica.

15. 9rolactinomas of the pituitary!

". Most often produce dysfunctional uterine &leeding in women.

$. Most commonly produce infertility in men.

C. When asymptomatic, are &est treated surgically early in the microadenoma

stage.

'. May enlarge during pregnancy, reuiring treatment with &romocriptine or

surgery.E. Commonly occur in patients with ME+ .

"nswer! '

'#SC)SS#*+! 9ituitary prolactinomas are the most common pituitary tumor

and cause amenorrhea, galactorrhea, or &oth in women. Men usually have

macroprolactinomas and e8perience symptoms of a space-occupying lesion

of the sella 0i.e., headache. " minority of men e8perience impotence and

infertility. "symptomatic prolactinomas remain sta&le over time and reuire

o&servation only. Symptomatic prolactinomas reuire treatment, usually with

&romocriptine. 9rolactinomas may enlarge during pregnancy and can produce

symptoms reuiring treatment with either &romocriptine or surgery.

9rolactiomas are seen in as many as 2A3 of patients with ME+ 1.


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A. Bypercortisolism!

". #s most often "C%B-dependent, owing to an "C%B-producing pituitary

adenoma.

$. #s &est diagnosed &y measurement of cortisol from a serum sample

collected at @ ".M.

C. #s attri&uta&le to an adrenal source if the &asal serum "C%B level is a&ove

1A pg. per ml., if the hypercortisolism is suppressed &y high-dose

de8amethasone, and if an adrenal tumor is visualied radiographically.

'. May &e caused &y small cell carcinoma of the lung, carcinoid tumors,

tumors of the endocrine pancreas, pheochromocytoma, or medullary thyroidcarcinoma 0M%C.

E. #n children is most often caused &y adrenocortical neoplasia.

"nswer! "'E

'#SC)SS#*+! CushingIs syndrome is most often 0@A3 to 5A3 "C%B-

dependent and is most often due to an "C%B-secreting pituitary adenoma

0CushingIs disease. Some 1A3 to A3 of "C%B-dependent CushingIs

syndrome is caused &y ectopic production of "C%B from small cellcarcinoma of the lung, carcinoid tumors, tumors of the endocrine pancreas,

pheochromocytoma, and M%C. "C%B-independent CushingIs syndrome

secondary to primary adrenal pathology occurs in 1A3 to A3 of cases in

adults and is the most common form in children. Measurement of cortisol in

two to three consecutive 2-hour collections of urine is the &est screening test

for CushingIs syndrome! plasma levels of cortisol show mared varia&ility,

and a single random level is not helpful in esta&lishing the diagnosis. "C%B-

independent CushingIs syndrome suppresses the pituitary and is diagnosed if

the &asal serum "C%B level is suppressed &elow ; pg. per ml., if the

hypercortisolism is not suppressed &y high-dose de8amethasone, or if the

metyrapone stimulation test is negative. %he de8amethasone suppression and

metyrapone tests do not, however, distinguish an adrenal from an ectopic


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"C%B cause of CushingIs since &oth suppress the pituitary. (adiographic

evidence of an adrenal tumor must &e supported &y &iochemical testing to

confirm that the adrenal is the primary cause of CushingIs syndrome.

1. 9rimary aldosteronism!

". 9roduces a syndrome of diastolic hypertension, hypoalemia, and edema.

$. #s suggested &y findings of serum potassium less than 4.; mE. per liter,

urinary potassium e8cretion greater than 4A mE. per day, upright plasma

renin &elow 4 ng. per ml., and a plasma aldosterone concentrationLplasma

renin activity ratio greater than A!1.

C. #s most often due to an aldosterone-producing adrenal adenoma, whichmay &e distinguished from idiopathic adrenal hyperplasia &y its sensitivity to

diurnal changes in "C%B and insensitivity to changes in posture.

'. May &e diagnosed in hypertensive patients &y demonstration of an adrenal

mass larger than 1 cm. on computed tomography alone.

E. #s &est treated surgically if it is due to either aldosteronoma or idiopathic

adrenal hyperplasia.

"nswer! $C

'#SC)SS#*+! 9rimary aldosteronism is a syndrome of diastolic

hypertension and hypoalemia6 edema typically is a&sent. %he diagnosis

relies on demonstration of hypoalemia with inappropriate aliuresis and

inappropriately elevated plasma aldosterone with suppression of plasma renin

following sodium loading. 9rimary aldosteronism most often is due to an

adrenal adenoma, which must &e distinguished from idiopathic adrenal

hyperplasia since resection of the adenoma is nearly always curative, whereas

adrenal resection for idiopathic adrenal hyperplasia is curative less than A3

of the time. C% evidence of adrenal tumor alone is inadeuate to diagnose

aldosteronism, even in a hypertensive patient.


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. "drenocortical carcinoma!

". May &e suspected in a patient with rapidly progressive CushingIs

syndrome and viriliing features or in asymptomatic patients with adrenal

tumors larger than ? cm on C%.

$. Most often is diagnosed early in its course when disease is confined to the

adrenal gland.

C. #s differentiated from &enign adrenocortical adenoma &y tumor necrosis,

hemorrhage, and cellular features of large hyperchromatic nuclei and more

than A mitoses per high-power field.

'. Should &e resected only if disease is localied to the adrenal gland6

otherwise treatment with mitotane is indicated.

E. Carries a poor prognosis! overall ;-year survival less than ;3."nswer! "E

'#SC)SS#*+! 9atients with adrenocortical carcinoma often present with

rapidly progressive syndromes of com&ined adrenocortical hormone e8cess.

Bowever, appro8imately half do not have syndromes of hormone e8cess &ut

present with a&dominal pain, increased a&dominal girth, weight loss, and

anore8ia. /urthermore, incidentally discovered adrenal masses larger than ?

cm. har&or carcinoma in as many as 53 of cases. "drenocortical carcinomais differentiated from adenoma &y pathologic demonstration of either local

invasion or distant metastases. Most patients with adrenocortical carcinoma

present with locally advanced 0stage ### or metastatic 0stage #G disease.

9rognosis for these patients is poor! ;-year survival is less than ;3 in most

series. 9atients with adrenocortical carcinoma should undergo primary

surgical resection or palliative surgical de&uling of locally advanced,

metastatic, or even recurrent disease since response of these tumors to

medical therapy, including mitotane, is poor.

4. "ddisonian crisis, or acute adrenocortical insufficiency!

". *ccurs only in patients with nown adrenal insufficiency or in those


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receiving long-term supraphysiologic doses of e8ogenous steroids.

$. Can mimic an acute a&domen with fever, nausea and vomiting, a&dominal

pain, and hypotension.

C. May cause electrolyte a&normalities, including hypernatremia,

hypoalemia, hypoglycemia, and hypercalcemia, as well as eosinophilia on

peripheral &lood smear.

'. Should &e diagnosed with the rapid "C%B stimulation test &efore steroid

replacement is instituted.

E. May &e effectively treated with intravenous stress-doseD glucocorticoid

and mineralocorticoid replacement.

"nswer! $

'#SC)SS#*+! "ddisonian crisis, or acute adrenal insufficiency, may &e seen

following even mild illness in patients with suppression of the hypothalamic-

pituitary-adrenal a8is. %his suppression can &e produced &y as little as 1 wee

of supraphysiologic stress dose steroids in the year &efore the stressful event.

"ddisonian crisis is a medical emergency that reuires prompt treatment

&ased on clinical suspicion. Clinical findings include fever, nausea and

vomiting, a&dominal pain, and hypotension.


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$. Bydration.

C. "lpha-adrenergic &locade, with or without &eta-adrenergic &locade.

'. 9reoperative Swan-an monitoring in all patients.

E. 9lanning removal through an anterior, posterior, or laparoscopic approach

&ased upon tumor localiation with C%, magnetic resonance imaging 0M(#,

and=or 141#-M#$.

"nswer! $CE

'#SC)SS#*+! 9rinciples of preoperative management for

pheochromocytoma include preoperative alpha-adrenergic &locade using

pheno8y&enamine or phentolamine. $eta-adrenergic &locade with

propranolol is then used selectively in patients who develop tachycardia, havea history of cardiac arrhythmia, or have primarily epinephrine-secreting

tumors. $eta-adrenergic &locade should &e undertaen only after successful

alpha &locade is esta&lished. 9atients with pheochromocytoma freuently

e8hi&it intravascular volume depletion, and careful hydration is mandatory.

Central venous pressure monitoring alone is helpful to guide hydration6 more

intensive monitoring with a Swan-an catheter is indicated for patients with

pre-e8isting heart disease. /ormerly, the anterior approach was preferred for

adrenalectomy as it facilitated complete a&dominal e8ploration and search for e8tra-adrenal pheochromocytoma. "ccurate preoperative localiation with

C%, M(#, and 141#-M#$ has allowed selective use of the posterior, or even

the laparoscopic, approach for adrenalectomy.

;. #ndications for surgical adrenalectomy include!

". "n adrenal mass larger than ? cm.

$. Bypertensive patients with aldosteronism that is "C%B insensitive and

posture sensitive and who also have multiple adrenal nodules on C%.

C. CushingIs syndrome secondary to adrenal neoplasms or to persistent

ectopic "C%B syndrome when the primary tumor is inopera&le.

'. 9heochromocytoma in adults and children.


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E. Congenital adrenal hyperplasia secondary to 1-hydro8ylase deficiency.

"nswer! "C'

'#SC)SS#*+! "drenalectomy is indicated for the management of adrenal

masses larger than ? cm. on C% since tumors of this sie har&or carcinoma in

more than 5A3 of cases. Surgical adrenalectomy is also the treatment of

choice for primary adrenal causes of CushingIs syndrome. Surgical

adrenalectomy may &e considered as an alternative to medical adrenalectomy

with metyrapone, aminoglutethimide, or mitotane in patients with ectopic

"C%B syndrome when treatment of the primary tumor is unsuccessful.

9atients with aldosteronism that is "C%B sensitive and posture insensitive

liely have an adrenal adenoma that is cura&le &y adrenalectomy."ldosteronism that is "C%B insensitive and posture sensitive is liely caused

&y idiopathic adrenal hyperplasia, which is &est managed medically with

spironolactone, triamterene, amiloride, or nifedipine. "drenalectomy

following preoperative alpha-adrenergic &locade, with or without &eta-

adrenergic &locade, and hydration is the treatment of choice of all

pheochromocytomas. "drenalectomy is not indicated in the management of

any of the congenital adrenal hyperplasias.

?. #ncidental adrenal masses!

". May &e seen in as many as 1A3 of a&dominal C% studies.

$. Most commonly represent pheochromocytoma6 adrenocortical adenoma,

adrenocortical carcinoma, and metastases from other primary cancers occur

less freuently.

C. May represent adrenocortical carcinoma if greater than ? cm. in diameter.

'. Should &e routinely evaluated &y measurement of 2-hour urine levels of

catecholamines and their meta&olites, cortisol, and aldosterone plus fine-

needle aspiration.

E. Should &e resected if &iochemically active, if greater than ? cm., or if they

grow over si8 monthsI follow-up.


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"nswer! CE

'#SC)SS#*+! %he incidental adrenal mass is seen in as many as 1.43 of

a&dominal C% scans performed for other reasons. "drenocortical adenomas

are most common, followed &y adrenocortical carcinoma, metastases from

other primary cancers, and pheochromocytoma. $iochemical evaluation must

weigh the prevalence of adrenal neoplasms against the conseuences of a

missed life-threatening diagnosis, as in pheochromocytoma. "ll adrenal

masses should &e evaluated for pheochromocytoma with measurement of 2-

hour urine catecholamines and their meta&olites. "ldosterone and cortisol

measurement are indicated if clinical features suggest aldosteronism or

CushingIs syndrome. /ine-needle aspiration of adrenal masses is indicated for clearly cystic lesions or if metastasis is suspected &ased on the presence of

another nown primary. /ine-needle aspiration is not routinely indicated in

the evaluation of adrenal lesions and is contraindicated until

pheochromocytoma is definitively e8cluded. "drenal lesions should &e

resected if they are functional, are larger than ? cm., or have enlarged during

follow-up.

7. Which of the following statements is true a&out the synthesis of thyroid

hormone and its physiology>

". %he iodine utilied in hormone synthesis is derived principally from

dietary sources.

$. %he role of thyroid-stimulating hormone 0%SB in thyroid physiology is

limited to regulation of the release of thyroid hormone in plasma.

C. Enough thyro8ine 0% 2 is stored in the normal thyroid to provide a

euthyroid state for 4 wees despite a&sence of iodine intae.

'. %he regulation of thyroid function involves pituitary, &ut not

hypothalamic, input.

"nswer! "C


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'#SC)SS#*+! #odine is necessary for the synthesis of thyroid hormone, and

appro8imately AA to ;AA mg is ingested daily. Most of it is a&sor&ed from

the small intestine and is cleared from the plasma &y secretion of thyroid

hormone. %SB is reuired for the normal production and secretion of thyroid

hormone. #t is generally accepted that %SB also has a ma:or role in thyroid

growth. %he thyroid gland has a storage reserve of appro8imately 4 wees.

%he principal regulatory mechanisms of the thyroid gland are the

hypothalamic-pituitary-thyroid control system and the intrathyroidal

regulatory systems. %(B is produced &y the superoptic and paraventricular

nuclei within the hypothalamus and passes down their a8ones. /ollowing

secretion into the hypophyseal portal &lood systems %(B passes to the

pituitary and induces stimulation of %SB secretion.

@. Correct statements a&out thyroid function tests include which of the

following>

". Contraceptive pills and pregnancy increase the amount of thyro8in-

&inding glo&ulin 0%$, and, conseuently, the total % 2 level.

$. "nticonvulsive medications and chronic de&ilitating illnesses decrease the

amount of %$ and, conseuently, the total % 2 level.C. #ntravenous pyleography can lower the rate of active iodine uptae &y the

thyroid.

'. " triiodothyronine 0% 4 suppression test that demonstrates

nonsuppressi&ility of thyroid function is compati&le with the diagnosis of

ravesI disease, to8ic adenoma, or functioning carcinoma.

E. "n increased serum cholesterol level in a hypothyroid patient indicates a

thyroid cause.

"nswer! "$C'

'#SC)SS#*+! Bormone &inding proteins are the principal intravascular

factors influencing total hormone concentration. Garious factors may cause

changes in the concentration of %$. Contraceptive pills and pregnancy


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increase the amount of %$, while anticonvulsive medications and chronic

de&ilitating disease may decrease the amount of %$. "dministration of

e8cess amounts of iodine may lower the rate of active iodine uptae in the

thyroid gland. %he thyroid suppression test is &ased on the principle that

administration of thyroid hormone does not suppress the patientIs thyroid

function when normal homeostatic mechanisms are disrupted. %hyroid

function is nonsuppressi&le in hyperthyroidism or in the presence of thyroid

hormoneLsecreting tumors. Serum cholesterol, deep tendon refle8 time, and

cardiovascular functions can &e measured to reflect hypothyroidism and

hyperthyroidism &ut do not give an indication of the etiology of

hypothyroidism.

5. Byperthyroidism can &e caused &y all of the following e8cept!

". ravesI disease.

$. 9lummerIs disease.

C. Struma ovarii.

'. BashimotoIs disease.

E. Medullary carcinoma of the thyroid.

"nswer! E

'#SC)SS#*+! Common types of hyperthyroidism include diffuse to8ic

goiter 0ravesI disease, named after the 'u&lin physician (o&ert raves who

descri&ed it in 1@4; &ut nown since its original description &y 9arry in 17@?

and descri&ed &y von $asedow in 1@2A and to8ic adenoma or to8ic

multinodular goiter 09lummerIs disease. )ncommon causes include

thyroto8icosis factitia, functioning metastatic thyroid carcinoma,

tropho&lastic tumors that secrete human chorionic gonadotropin 0having

thyroid-stimulating properties, inappropriate secretion of thyrotropin &y

pituitary tumors, struma ovarii, iodide-induced hyperfunction, and thyroiditis.


22/71

4A. Which of the following is true a&out the use of radioiodine to treat

hyperthyroidism>

". #f hyperthyroidism is secondary to radioiodine use, it will occur within

years of treatment.

$. %here is a maredly increased ris of future thyroid cancer following

radioiodine therapy.

C. %he ris of leuemia following radioiodine therapy is appro8imately 1A3.

'. Mutation a&normalities occur in 1;3 of fetuses in utero following internal

treatment of the mother with radioiodine during pregnancy.

E. (adioiodine may pass through the placenta and lactating &reast to produce

hypothyroidism in a fetus or infant.

"nswer! E

'#SC)SS#*+! Bypothyroidism secondary to radioiodine therapy increases

in freuency with time to @;3 after ; years. %here has &een no demonstration

of an increase in malignancies following radioiodine therapy. (adioactive

iodine can cross the placenta and lactating &reast to produce hypothyroidism

in a fetus or a nursing infant and is, therefore, contraindicated.

41. "rrange the following complications of thyroid surgery 0&ilateral su&total

thyroidectomy in decreasing order of incidence in patients with ravesI

disease.

".


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additional increase in su&seuent years. %he associated mor&idityrelated

primarily to damage to the recurrent laryngeal nerves and parathyroid glands

is estimated to &e A.;3 to 4.A3.

4. %he most common cause of goitrous hypothyroidism in adults is!

". ravesI disease.

$. (iedelIs thyroiditis.

C. BashimotoIs disease.

'. de QuervainIs thyroiditis.

"nswer! C

'#SC)SS#*+! BashimotoIs disease was first descri&ed in Napan &y Baaru

Bashimoto in 151 and is the &est-nown of the immunologic thyroid

diseases. #t is the most common cause of goitrous hypothyroidism in adults

and of sporadic goiter in children. %he incidence is A.4 to 1.; cases per 1AAA

population per year and it is 1A to 1; times more common in women than in

men, with the highest incidence in the group aged 4A to ;A years.

44. %herapy for BashimotoIs disease includes!

". (adioiodine.

$. "ntithyroid medications.

C. Su&total thyroidectomy.

'. +one of the a&ove.

"nswer! '

'#SC)SS#*+! %here is no specific treatment for BashimotoIs disease.

9atients are usually followed medically, and replacement therapy with % 2 is

&egun in patients with hypothyroidism that is symptomatic or associated with

a goiter that is causing pressure symptoms. Early initiation of thyroid

hormone therapy has &een recommended &y many to prevent further thyroid


24/71

enlargement and reduce the ris of my8edema, especially in postpartum

patients. Surgical reduction of goiter should &e performed if severe pressure

symptoms that have not responded to corticosteroid therapy are present. %his

usually consists of su&total thyroidectomy. $iopsy to rule out malignancy in

nodules suspicious for thyroid carcinoma 0usually papillary or lymphoma is

indicated. #f carcinoma is suspected, lo&ectomy should &e performed, and if

froen section demonstrates carcinoma, su&total or total thyroidectomy

should &e performed.

42. #ndications for surgical thyroidectomy for ravesO disease include which

of the following>

a. *cular involvement

&. Symptomatic large goiter

c. Women of child&earing age

d. Concomitant thyroid nodule

e. "ll of the a&ove

"nswer! &, c, d

"ntithyroid drugs are the initial therapy in most patients with ravesO

disease, either as a definitive therapy or in preparation for 141# therapy or

surgical a&lation. $ecause of the high failure rate of long-term treatment with

thionamides, the use of these drugs as definitive treatment has decreased.

'raw&acs include the important A.;3 incidence of agranulocytosis and a

recurrence rate as high as 243 during the first year when the drug is stopped.

/ive years after treatment only ;3 of patients remain in remission. )nlie

other definitive treatments, hypothyroidism does not occur as a result of

thionamide treatment if an appropriate dosage is used. 141# has &een used as

definitive treatment for patients with ravesO disease for many years with

predicta&le and long-lasting good results in most patients. #t has few, if any,

serious side effects. #t is a&lative to the thyroid gland and hypothyroidism is a


25/71

nearly inevita&le result of effective therapy, although it may tae years to

&ecome clinically apparent. "&out 7A3 of patients treated with 141# are

hypothyroid within 1A years of treatment. %he ris of recurrence of

hyperthyroidism after an initial response is less than ;3. Most adult patients

in the )nited States are treated with 141# as definitive treatment for ravesO

disease. E8ceptions are women in the child&earing years where a su&seuent

fetus would &e affected, patients with concomitant thyroid nodules where

carcinoma is a concern, those with e8tremely large glands and, increasingly,

those who are opposed to 141# therapy. %hyroidectomy is an important

alternative in selected patients with ravesO disease. "lthough controversial

in the past, it now appears that ocular involvement does not respond more

favora&ly to thyroidectomy than to 141# a&lation.

4;. Which of the following statements regarding anatomic relationships of

the thyroid gland are true>

a. %he middle thyroid artery is intimately related to the superior laryngeal

nerve

&. %he superior thyroid artery is usually the first &ranch of the e8ternal carotidartery

c. %hyroidea ima arteries are found in appro8imately A3 of individuals

d. %he parathyroid glands may lie within the pretracheal fascia

"nswer! &, d

%he thyroid gland is a vascular organ supplied &y four main arteries! two

superior and two inferior. %he superior thyroid artery usually arises as the

first &ranch of the e8ternal carotid artery :ust a&ove the &ifurcation of the

common carotid artery. %he superior thyroid artery descends medially on the

surface of the inferior pharyngeal constrictor muscle to divide into an anterior

and posterior &ranch at the ape8 of the thyroid lo&e on its anteromedial

surface. #ts relation to the e8ternal &ranch of the superior laryngeal nerve is


26/71

important during thyroid lo&ectomy. %he inferior thyroid arteries usually arise

from the thyrocervical truns and ascend &ehind the carotid sheath &efore

passing downward and medial to enter the thyroid gland at its middle portion.

%here are no arteries directly entering the lower poles from &elow with the

e8ception of a thryoidea ima artery that may replace an a&sent inferior artery.

%hyroidea ima arteries arise from either the innominate artery or aorta in 13

to 23 of individuals, entering the lower surface of the isthmus after coursing

on the trachea.

%he pretracheal fascia is referred to as the thyroid sheath and it varies in

consistency and completeness among individuals. 9osteromedially, it is

usually condensed and firmly attaches the thyroid gland to the upper two or

three tracheal rings and the cricoid cartilage. %he superior parathyroid glandmay lie &etween the sheath and the thyroid capsule, within the sheath,

posterior to it in a potentially open plane, or occasionally anterior to the

sheath. %he inferior parathyroid gland liewise may &e within the sheath,

particularly when the gland is adherent to the lower pole of the thyroid.

4?. (adioactive iodine is effective treatment for metastatic lung disease for

which of the following thyroid neoplasms>

a. BPrthle cell carcinoma

&. 9apillary carcinoma

c. /ollicular carcinoma

d. Medullary carcinoma

e. "naplastic carcinoma

"nswer! &, c

(adioactive iodine is used only in patients who have differentiated thyroid

carcinomas. #t is of no value in the treatment and follow-up of patients with

BPrthle cell, medullary or anaplastic carcinomas. Most papillary carcinomas

are capa&le of taing up radioactive iodine. Most papillary carcinomas in


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patients under ;A-years of age do so, providing that the patient has had a total

thyroidectomy and there is no normal thyroid tissue to compete for the 141#.

"&out A3 of all papillary carcinomas do not trap sufficient iodine for

imaging or therapy. %hese are usually patients with papillary carcinoma

variants! a tall cell variant of papillary carcinoma, insular carcinoma, or clear

cell carcinoma.

+early all metastatic follicular carcinomas retain the a&ility to trap 141#

sufficiently for imaging and for therapy. Even well-differentiated papillary

and follicular carcinoma cannot compete successfully for 141# with normal

thyroid tissue and unless this has &een removed or su&seuently a&lated with

an initial dose of 141#, many metastases cannot &e detected or treated.

47. %he types of thyroiditis that can cause a&normalities of surgical

significance are which of the following>

a. Chronic lymphocytic thyroiditis 0Bashimoto disease

&. (iedel struma

c. "cute 0viral thyroiditis

d. ranulomatous 0su&acute thyroiditis"nswer! a, &, d

%here are three types of thyroiditis that can cause thyroid a&normalities of

surgical significance. %he most common is chronic lymphocytic 0Bashimoto

thyroiditis, an autoimmune disease that can occur in any age group.

*ccasionally, Bashimoto disease causes unilateral thyroid enlargement that

simulates malignancy. %he rarest form of thyroiditis is (iedel struma which

can mimic a diffuse thyroid carcinoma &ecause of the fi&rotic infiltrative

process that results. Bashimoto thyroiditis is associated with reduced

functional capacity of the thyroid which increases %SB secretion, and a goiter

develops. $ecause of the associated fi&rosis, a nodular goiter or neoplasm is

suggested. %hyroidectomy may &e indicated for treatment of a solitary


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nodule, particularly if it is cold, suspicious, definitely malignant or solid, and

fine needle aspirate is indeterminate.

ranulomatous, 'eQuervain, and su&acute thyroiditis are terms that refer to a

disease that usually occurs in young women within wees of an upper

respiratory or other viral infection. %he disease is usually self-limited, &ut

may persist for several months longer. #n unusual patients, the disease may &e

confined to one lo&e and result in a firm, slightly tender mass suggesting

carcinoma.

a. Superior thyroid arteries

&. #nferior thyroid arteries

c. %hyroidea ima arteries

d. 9arathyroid arterial &ranches directly from the e8ternal carotid artery

e. Bighly varia&le

"nswer! &


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%he principal &lood supply to &oth parathyroid glands is the inferior thyroid

artery. 9arathyroid glands invaria&ly have a single end artery supplying them,

and if the main trun of the inferior thyroid artery is ligated during

thyroidectomy, there is no collateral &lood supply to maintain their via&ility.

#t is prefera&le to divide only the &ranch of the inferior thyroid artery medial

to those that supply either of the parathyroid glands. %his reuires individual

clamping of smaller vessels under the thyroid sheath as these vessels

penetrate into the thyroid capsule.

a. Seventy to @A3 of new cases of thyroid carcinoma in the )nited States are

of the papillary type

&. %otal ipsilateral lo&ectomy and isthmus resection are adeuate therapy forminimal thyroid carcinoma

c. Microscopic evidence of multicentric disease is present in 7A3 to @A3 of

cases

d. +early all patients less than 1; years of age have metastatic disease in local

lymph nodes

"nswer! a, &, c, d

Seventy to @A3 of the 11,AAA new patients with thyroid carcinoma diagnosed

annually in the )nited States have papillary carcinoma. 9apillary carcinomas

of the thyroid include minimal thyroid carcinoma, intrathyroidal, and

e8trathyroidal 0invasion through the true thyroid capsule disease. Minimal

thyroid carcinoma refers to those papillary carcinomas that are less than 1 cm


30/71

in diameter and not associated with any clinically apparent lymph node

metastases. #n contrast to clinically significant papillary carcinomas, these are

common and are found in 3 to 143 of adult thyroid glands serially

sectioned after autopsy studies of individuals who have died from other

causes. /or tumors &etween A.; and 1 cm, a total lo&ectomy and isthmus

resection are satisfactory treatment.

Most clinically significant papillary carcinomas are 1 to 2 cm in diameter and

are contained within the thyroid capsule. Multicentricity is relatively

common and can &e found on gross sectioning of the thyroid gland in A3 to

4A3 of cases. /urthermore, after serial sectioning of the entire thyroid gland

in patients with papillary carcinoma, microscopic foci are found in 7A3 to

@A3.


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(adioisotope scanning measures the functional activity of the thyroid gland

and maps its correlation with physical findings. /or routine scanning, 141#

scanning has &een replaced &y either 14# or 55m%c. $ecause of the lower

radiation e8posure, cost and easy use, 55m%c is preferentially used. %he

differential diagnosis of a solitary nonfunctioning nodule includes carcinoma,

colloid nodule, nonfunctioning adenoma, and cyst. %he prevalence of

carcinoma ranges from ;3 to A3 in cold nodules and such lesions reuire

further evaluation. #f the scan detects other nonfunctioning areas in addition

to the palpa&le nodule, the gland is at low ris for carcinoma &ecause most

patients with this finding have a multinodular goiter. " solitary, discrete area

of increased activity is more often found in a young patient with an otherwisenormal thyroid gland. Multiple hot spots are typically found in an older

patient with a multinodular goiter.

" functioning solitary nodule that is independent of %SB is considered an

autonomous nodule and can &e the cause of hyperthyroidism. #t is hot on

scintigraphic scan. %he presence of a cold nodule is insufficient information

to determine a treatment plan. "lthough nearly all carcinomas are cold, most

cold nodules are &enign. /ine needle aspiration cytology is considered the

most relia&le means of evaluation for the diagnosis of thyroid nodules thatare nonfunctional or hypofunctional &y nuclide scan.

21. Which of the following pharmacologic agents can &e used in the

treatment of thyroto8icosis to &loc the production of thyroid hormone>

a. 9ropylthiouracil

&. 9ropranolol

c. Methimaole

d. Car&imaole

e. #odine

"nswer! a, c, d, e


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" num&er of su&stances interfere with normal production of thyroid hormone

&y &locing one of the relevant enymatic steps. #odine was the first effective

drug to &e used in the treatment of thyroto8icosis. #t can &loc the

organification and coupling steps in thyroid hormone synthesis as well as

prevent the release of thyroid hormone. /urthermore, iodine in large doses

pro&a&ly inhi&its the a&ility of %SB to stimulate cyclic "M9 release at the

follicular cell mem&rane.

Commonly used antithyroid drugs are propylthiouracil 09%), methimaole

0%apaole and car&imaole. Car&imaole is widely used in reat $ritain,

only 9%) and methimaole are commonly used in the )nited States. 9%)

interferes with the incorporation of iodine into the tyrosine residues ofthyroglo&ulin, thus preventing o8idation of iodide to iodine. #t also inhi&its

the peripheral conversion of %2 to %4. "lthough &oth 9%) and methimaole

are thionamides, methimaole does not have this peripheral effect, maing

9%) the preferred drug for patients with thyroid storm. "&out 43 of patients

taing 9%) demonstrate at least one side effect during the first 4 months of

therapy whereas the prevalence with methimaole is a&out 73. %hese range

from minor sin rashes to agranulocytosis that can &e irreversi&le.

&-adrenergic antagonists have &een used in the treatment of hyperthyrodism.9ropranolol is the most widely used of these drugs. Bowever, &-&locade

does not alter thyroid function per se. (ather, its effect is to provide

symptomatic relief of hyperthyroidism &ecause of interference with the action

of thyroid hormones at the cellular level.

2. " 2;-year-old woman has a solitary, nonfunctioning thyroid nodule and

fine needle cytology is nondiagnostic. Which of the following is the initial

surgical procedure of choice>

a. %otal e8tracapsular thyroidectomy

&. Su&total thyroid lo&ectomy and resection of the isthmus


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c. %otal e8tracapsular thyroid lo&ectomy, resection of the isthmus, and

modified unilateral nec dissection

d. %otal e8tracapsular thyroid lo&ectomy and resection of the isthmus

"nswer! d

%otal e8tracapsular thyroid lo&ectomy and isthmus resection is the procedure

of choice when a decision has &een made to surgically remove a thyroid

nodule. %he entire lo&e with the isthmus is su&mitted for froen-section

pathologic e8amination if fine needle aspirate has not already resulted in a

definitive diagnosis of carcinoma. #n performing total lo&ectomy, &oth

parathyroid glands are carefully preserved with their &lood supply. %his is

done in the event that total thyroidectomy is necessary if either the froen or permanent histologic sections confirm the presence of thyroid carcinoma.

%otal lo&ectomy offers the &est opportunity for accurate histologic diagnosis

and is associated with the lowest incidence of complications when the need

for reoperation is considered. #n one e8perience, @AA consecutive cases of

total unilateral lo&ectomy were performed for &enign or malignant nodules

suspected of cancer, and no permanent recurrent laryngeal nerve palsies

occurred. 9rimary total lo&ectomy is safer than a partial lo&ectomy followed

&y resection of the residual lo&e after a delayed diagnosis of malignancy.(eoperation to complete a lo&ectomy is associated with a greater ris to &oth

recurrent laryngeal nerve and the parathyroids on the ipsilateral side.

"lthough there is controversy as to whether a total lo&ectomy and isthmus

resection or a total thyroidectomy is the &est definitive operation for

unilateral papillary carcinoma, a su&total lo&ectomy is universally considered

an inadeuate operation. " definitive cancer operation can &e accomplished

with one procedure in @A3 of the cases when a silled thyroid pathologist is

availa&le for froen-section interpretation.

24. Which of the following statements regarding fine needle aspiration

cytology of a thyroid nodule are true>


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a. #t differentiates neoplastic and nonneoplastic nodules in most cases

&. #t does not allow differentiation of papillary, medullary and anaplastic

carcinoma

c. #t cannot differentiate malignant and &enign follicular or BPrthle cell

neoplasms

d. #t is not recommended when a patient has a history of head and nec

radiation

"nswer! a, c, d

When interpreted &y a silled cytologist, fine needle aspiration is highly

accurate and is considered the preferred method of selecting patients withthyroid nodules for surgery. +early @A3 of patients with thyroid nodules

were spared surgical e8ploration as a result of such studies in one report.

$ecause of the ris of false-negative diagnoses 01A3, advocates of this

techniue emphasie the importance of clinical :udgment in addition to the

cytologic study in selecting operative candidates.

#n most cases, fine needle aspiration cytology ena&les the pathologist to

distinguish nonneoplastic from neoplastic nodules and to identify the type of

malignant tumor. 9apillary, medullary, and anaplastic carcinoma all have atypical cytologic appearance. Cytologic studies cannot differentiate malignant

from &enign follicular or BPrthle cell neoplasms. #n this case, a definitive

diagnosis depends on histologic e8amination of the entire e8cised tumor.

/ine needle aspiration has dramatically reduced the num&er of diagnostic

surgical operations for &enign lesions in centers where it is used e8tensively.

#n patients with thyroid nodules and a history of previous head and nec

radiation, operation is generally recommended regardless of cytologic

findings. #n these patients, &oth &enign and malignant lesions may develop

and the chances of sampling error are considera&le.

22. Byperthyroidism results from all of the conditions noted &elow. *f the


35/71

following which commonly reuire surgical management>

a. ravesO disease

&. Struma ovarii

c. /unctioning metastatic thyroid carcinoma

d. %o8ic diffuse goiter

e. Single to8ic thyroid nodule

"nswer! a, d, e

Byperthyroidism is associated with clinical manifestations related to an

e8cess of thyroid hormone. %here are three causes of primary concern to the

surgeon. ravesO disease, or to8ic diffuse goiter, is most common, accountingfor more than @A3 of all patients with hyperthyroidism. %he other two

relevant causes of hyperthyroidism are to8ic nodular goiter and a single to8ic

nodule. Common causes of hyperthyroidism that rarely reuire surgery are

postpartum thyroiditis, iodine-induced hyperthyroidism, self-administered or

iatrogenic hyperthyroidism, struma ovarii, functioning metastatic carcinoma

and several rare forms of thyroiditis.

2;. Which of the following statements regarding medullary carcinoma of the

thyroid are true>

a. "ppro8imately 7;3 of all cases are hereditary

&. %he overall 1A-year survival rate is less than 1A3

c. Medullary carcinoma of the thyroid is associated with &oth multiple

endocrine neoplasia ##a 0ME+ ##a and multiple endocrine neoplasia ##&

0ME+ ##& syndromes

d. 9rophylactic total thyroidectomy is recommended for ME+ ##a and ME+

##& patients after the age of 1A years

"nswer! c


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Medullary carcinoma of the thyroid 0MC% accounts for a&out 73 of all

malignant tumors of the thyroid. #t is familial in A3 to 4A3 of all cases and

its secretion of a &iologic marer 0calcitonin allows detection of its presence

with the tumor is too small to palpate. MC% appears in three clinical settings.

%he first is a sporadic tumor, usually in patients 4A years or older. Second,

MC% occurs as a component of the ME+ ##a syndrome with or without

adrenal medullary disease 0pheochromocytoma or hyperparathyroidism. "

family history of thyroid carcinoma with or without pheochromocytoma is

invaria&ly present. MC% in the ME+ ##a syndrome is always &ilateral and

multicentric and arises from C-cell hyperplasia. MC% usually does not

develop &efore age 1 and is almost always clinically apparent &efore age 4A.


37/71

a. +ormally a&out A3 of %4 is secreted directly from the thyroid gland

&. %he thyroid gland is the only endogenous source of %2

c. E8cess thyroid hormone results in an increase in the num&er of "%9-

dependent sodium pumps on the cell mem&rane

d. %he ma:ority of thyroid hormone in circulating plasma is &ound to

al&umin, thus limiting the availa&ility of the meta&olically active form

"nswer! a, &, c

%he thyroid is the only endogenous source of %2, whereas most %4 is

produced &y the peripheral conversion of %2. %his taes place in the liver,

muscle, idney and anterior pituitary. )nder normal circumstances, onlya&out A3 of %4 is secreted directly from the thyroid gland. #n some thyroid

diseases 0e.g., ravesO disease and to8ic nodular goiter, the proportion of %4

secreted directly &y the thyroid may &e maredly increased.

*nce thyroid hormones are released into the circulation, they are &ound to

thyroid-&inding glo&ulin 0@;3, al&umin 01A3 and transthyretin

0preal&umin. %hese &inding proteins allow the thyroid hormones to remain

solu&le in plasma, contri&uting to systemic distri&ution to various target-cell

populations. " limited amount of thyroid hormones circulates freely in the plasma in meta&olically active form 0free %2, free %4.

"t the cell mem&rane, an e8cess of thyroid hormone results in an increased

num&er of "%9-dependent sodium pumps, thus increasing resting energy

e8penditure and o8ygen consumption. %hyroid hormone also facilitates the

transport of glucose and amino acids across the cell mem&rane. #n addition,

%4-induced mitochondrial o8idation of su&strate results in increased "%9

production.

27. %he definitive treatment of choice for to8ic multinodular goiter is>

a. %otal thyroidectomy


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&. $ilateral su&total thyroidectomy

c. )nilateral total lo&ectomy on the side of dominant disease

d. 141# treatment

"nswer! &

Byperthyroidism in the patient with a multinodular goiter usually develops in

women after age ;A &ut is seen occasionally in younger patients. Most

patients have had a nonto8ic nodular goiter for many years. 9referred

treatment for most patients with to8ic multinodular goiters is thyroidectomy

after adeuate preparation renders the patient euthyroid. 141# may &e an

alternative in selected poor-ris patients with goiters that are not causing

airway compression. "lthough 141# can &e used to treat the hyperthyroidism,larger and often repeated doses of 141# may &e reuired. 141# does not

significantly reduce the goiter sie and may, &ecause of radiation-induced

thyroiditis, cause acute enlargement. %his may &e haardous in the patient

with some degree of pree8isting airway compression. "ny airway symptoms,

particularly in patients with su&sternal goiters, should &e considered strong

contraindications to the use of 141#.

Standard surgical treatment of to8ic nodular goiter has consisted of &ilateral

su&total thyroidectomy. (emnant sie is not as important as the e8cision ofall autonomous nodules. $ecause thyroid replacement or suppression is used

routinely to prevent recurrence of goiter when a su&total resection is done,

the ris of hypothyroidism is not a consideration in determining remnant sie.

"lternative procedures are total lo&ectomy with isthmus resection and

contralateral su&total lo&ectomy, or total thyroidectomy. %he latter is not

demonstra&ly superior and may have more technical complications.

2@. " ;A-year-old male has undergone an ipsilateral thyroid lo&ectomy and

isthmus resection for what appeared on froen section to &e a &enign nodular

lesion .A cm in diameter. Seventy-two hours later the final pathology returns

and the diagnosis is a high-grade angioinvasive follicular carcinoma. What do


39/71

you recommend>

a. 55m%c &one scan to rule out occult &one metastases

&. #psilateral radical nec dissection

c. %otal thyroidectomy

d. *&servation with seuential 141# scans every 4 months

"nswer! c

/ollicular carcinoma accounts for a&out 1A3 of all new carcinomas of the

thyroid. Most patients are those with minimal invasion of the capsule or

vessels within the neoplasms. Such tumors are seldom diagnosed definitively

&y either needle aspiration cytology or &y froen-section diagnosis at the timeof lo&ectomy. Most freuently, the diagnosis is made after the study of

permanent sections. Microinvasive encapsulated follicular carcinomas are

rarely associated with metastatic lymph nodes and distant metastases

involving &one are also rare at the time of diagnosis.

"ngioinvasive follicular carcinomas are usually large and freuently show

venous invasion of perithyroidal and lateral nec veins at the time of

diagnosis. %hey may have already metastasied to different sites, most

freuently the &one. %hese tumors are often diagnosed at the time ofoperation &ecause of these characteristics. Most patients younger than 2A do

well, &ut patients older than ;A years have a guarded prognosis. /ollicular

carcinomas of the thyroid are treated &y total thyroidectomy.


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rule out occult &one metastases. 9atients with large or high-grade

angioinvasive lesions reuire total thyroidectomy.

49. In 1990 a National Institutes of Health Consensus Dev

pment Conference reviewed the available evidence regarding the management of

asmptomatic primar hperparathroidism. !he panel concluded that surgical

intervention was indicated for which of the following indications"

a. #ge less than $0 ears of age

b. %educed creatinine clearance

c. 9resence of idney stone0s 0as detected &y a&dominal radiograph

d. Su&stantial reduced &one mass as determined &y direct measurement

e. Maredly elevated 2-hour urinary calcium e8cretion

"nswer! a, &, c, d, e

"ll of the indications listed a&ove are considered indications for operative

treatment of asymptomatic patients with primary hyperparathyroidism. %heir

conclusions regarding operative indications are summaried in %a&le ;7-@.

%he +#B Consensus 'evelopment Conference mandated close 0every ?

months follow-up for patients with nown primary hyperparathyroidism not

treated &y operation. #n addition, surgery was agreed upon for those patients

in whom medical surveillance was neither desira&le nor suita&le, such as

when the patient reuests surgery, consistent follow-up is unliely, co-

e8istent illness complicates management, or if the patient is young 0 ;A year

of age. #n one recent study of a group of 12 asymptomatic patients followed

without operation, after 1A years, more than A3 of the patients had reuiredsurgery for an increase in serum calcium to greater than 11 mg=d< or for

specific complications attri&uta&le to the disease. "nother A3 were lost to

or declined follow-up. %he remainder either died of unrelated causes or had

persistent asymptomatic disease. %his remains an area of considera&le


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controversy. %he &est availa&le recommendations are derived from this

*cto&er 155A +#B Consensus 'evelopment Conference. ;A. Which of the

following statements regarding medullary carcinoma of the thyroid are true>

a. $ilateral medullary carcinoma of the thyroid occurs in every patient withmultiple endocrine neoplasia 1, a or & &. Medullary carcinoma of the

thyroid accounts for appro8imately one-third of all thyroid malignancies c.

A3 of medullary carcinoma of the thyroid cases are familial d. 9rovocative

testing with pentagastrin and calcium infusion for family mem&ers at ris for

medullary carcinoma of the thyroid is diminished in importance &y the recent

development of specific genetic testing "nswer! a, c, d Medullary thyroid

carcinoma accounts for a&out 1A3 of all thyroid malignancies, and A3 of

cases occur in the familial setting of ME+ a, ME+ $, or familial non-

ME+ medullary thyroid carcinoma. #t is usually the first tumor that develops

in these patients and typically occurs in the second or third decade of life.

%umors are virtually always &ilateral and develop in multiple areas of the

middle and upper portions of the thyroid lo&e. 'etection has historically &een

&ased on ela&oration of calcitonin, particularly in response to provocative

testing &y the potent secretagogues calcium and pentagastrin. 9atients with

medullary carcinoma of the thyroid have striing increases in plasma

calcitonin levels after provocative testing, which allows them to &e readily

identified. $y employing provocative testing in indred mem&ers at ris for

disease, medullary carcinoma of the thyroid was diagnosed at a preclinical

stage, and a greater percentage of these patients were cured &y surgical

therapy. With genetic testing now availa&le, early treatment of medullary

thyroid cancer should &e possi&le for all affected people, to hopefully

enhance the num&er of people cured of this cancer. %he ME+ 1, a and &syndromes are inherited in an autosomal dominant fashion with complete

penetrance &ut varia&le phenotype. $ilateral medullary carcinoma of the

thyroid occurs in every affected patient. ;1. While awaiting surgery on a

BM* waiting list, a ;A-year-old female with primary hyperparathyroidism is


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admitted to the hospital with oliguria, confusion, nausea and vomiting,

muscle weaness and a serum calcium of 14.; mg=d a. "dminister 1 gm of

hydrocortisone S%"% &. $egin an #G E'%" 0chelating agent infusion S%"%c. "dminister #G Mithramycin and calcitonin concurrently and proceed to

#C) for cardiac monitoring d. $egin a normal saline infusion at R

maintenance volume followed &y 1mg=g furosemide #G e. +one of the

a&ove "nswer! d 9atients with mared hypercalcemia or severe symptoms

should &e admitted to the hospital for careful o&servation and monitoring.

%he mainstay of therapy is intravenous hydration, prefera&ly with normal

saline in sufficient uantities to maintain the urine output a&ove 1AA m


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ileal resection d. $reast cancer e. "ll of the a&ove "nswer! a, &, d Multiple

causes of hypercalcemia include the following! Malignancy Gitamin " or '

into8ication %hiaide diuretics Byperthyroidism Mil-alali syndrome

Sarcoidosis and other granulomatous diseases /amilial hypocalciurichypercalcemia #mmo&iliation 9agetOs disease a. 9roceed to *( for e8ploration of

the operative site &. "dminister ; ml of 1A3 calcium gluconate

intravenously c. *&tain a serum magnesium measurement and administer

intravenous magnesium chloride S%"% d. *&tain a C% scan of the head to

evaluate the possi&ility of &rain metastases "nswer! & 9ostoperativehypoparathyroidism commonly develops after total thyroidectomy for

malignancy. Most patients undergoing operation on the thyroid e8perience

some alteration in serum calcium. %he hypocalcemia is usually transient and

is not treated unless significant symptoms develop. %he plasma calcium


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usually reaches its nadir at 2@ to 7 hours after surgery and then slowly

returns to normal over to 4 days. /or these reasons, careful postoperative

monitoring of serum calcium levels is essential. /or acute symptomatic

hypocalcemia, calcium should &e administered intravenously. )sually A to4A m< of 1A3 calcium gluconate is infused over a 1; to A minute period

and then ;A to 1AA m< are administered over the ne8t 1 hours in adults.

Calcium gluconate is less irritating to the veins than calcium chloride, and the

calcium release is slower without the ris of overcorrection. Serum

magnesium should always &e measured and hypomagnesemia should &e

corrected if present. %his is not the first priority for this patient. Symptoms

should never &e allowed to progress to the point demonstrated in this patient.

9ostoperative routines include careful monitoring of the serum calcium until

sta&le. %here is no evidence that this patient has a postoperative surgical

pro&lem such as a cervical hematoma.


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associated with some diseases of the gastrointestinal tract, &one or other

endocrine organs. *ccasionally, with prolonged secondary stimulation, the

hyperfunctioning glands are no longer physiologically responsive to an

increased ionied calcium. %his rare, relatively autonomous state is referredto as tertiary hyperparathyroidism and develops most commonly after renal

transplantation when the defect in calcium homeostatis is corrected. %he

numerical values for calcium and 9%B here are consistent with primary

hyperparathyroidism. (elation &etween serum immunoreactive parathyroid

hormone 0i9%B and serum calcium in patients with hypoparathyroidism,

pseudohypoparathyroidism, ectopic hyperparathyroidism, and primary,

secondary, and tertiary hyperparathyroidism. 91M, guinea pig antiserum

1M. 0"fter Clar *B, Way a. (ecurrent postoperative hypercalcemia occurs in appro8imately

A3 of patients with this clinical scenario &.


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correct initial diagnosis and review of the original operative and pathology

reports are essential. #t is generally agreed that localiation studies do have a

place in the management of recurrent disease. +oninvasive methods are

employed first, and if these are unsuccessful in identifying the diseasedgland, selective angiography and venous sampling for 9%B are employed.

Selective angiography appears to &e the most accurate techniue,

successfully localiing ;A3 to @A3 of parathyroid glands that cannot &e

detected &y any other modality. Surgical ree8ploration can &e difficult.

enerally the nec is e8plored first after which the mediastinum is e8amined

if this is unproductive. Surgical ree8ploration is successful in e8perienced

hands in ?A3 to @A3 of cases. %here is, however, an increased incidence of

complications. )nilateral recurrent nerve in:ury occurs in ;3 to 1A3 of

patients and permanent hypoparathyroidism occurs in 1A3 to A3 of patients

postoperatively. ;?. Which of the following statements regarding calcium and

phosphate meta&olism are true> a. 9arathyroid hormone e8cess produces a

net increase in daily urinary calcium e8cretion &. Calcitonin is essential for

the normal control of calcium meta&olism in adult humans c. 9arathyroid

hormone is the single most important regulator of calcium and phosphate

meta&olism in humans d. 1,; dihydro8yvitamin '4 0calcitriol is the active

form of vitamin ' in humans "nswer! a, c, d %he primary hormonal

regulators of calcium and phosphate meta&olism are parathyroid hormone

09%B, vitamin ' and calcitonin. 9arathyroid hormone appears to &e the

single most important hormonal regulator of calcium and phosphate

meta&olism in humans. #t has direct effects on the seleton and idney and

indirect effects on the intestine, mediated through vitamin '. Sustained

elevations of 9%B stimulate osteoclasts and inhi&it osteo&lasts leading toa&sorption of calcium from &one. #n the idney, 9%B produces an increase in

rea&sorption at any given concentration of e8tracellular fluid calcium,

although e8cess secretion, &ecause of the hypercalcemia, results in a net

increase in daily urinary calcium e8cretion. Gitamin '4, or cholecalciferol, is


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produced normally &y the action of sunlight on 7-dehydrocholesterol in the

sin. #t is then hydro8ylated in the liver 0; position and idney 01 position

to form the active 1,; dihydro8yvitamin '4 0calcitriol. %his is the active

form of Gitamin ' in humans. Calcitonin is a 4-amino acid protein produced &y the parafollicular C cells of the thyroid. %otal thyroidectomy, with removal

of all the C cells, is well tolerated, and it has &een concluded that calcitonin is

not essential for the normal control of calcium meta&olism in adult humans.

Calcitonin does inhi&it &one resorption and can produce hypocalcemia in

e8perimental animals. #t also increases urinary calcium and phosphate

e8cretion. ;7. Multiple Endocrine +eoplasia 0ME+ & is characteried &y

which of the following findings> a. Medullary carcinoma of the thyroid,

pheochromocytoma, mucosal neuromas, and a distinctive marfanoid ha&itus

&. 9arathyroid hyperplasia, pancreatic islet cell tumors, and pituitary

adenomas c. Medullary carcinoma of the thyroid, pheochromocytoma, and

parathyroid hyperplasia d. 9arathyroid carcinoma, pheochromocytoma and

chronic pancreatitis "nswer! a %he multiple endocrine neoplasias are familial

disorders typically characteried &y predisposition to the development of

tumors of multiple endocrine organs. %hese disorders are all inherited in an

autosomal dominant fashion, and the tumors tend to &e multicentric. %he

tumors may &e &enign or malignant and may occur metachronously or

synchronously. ME+ 1 is characteried &y the concurrence of parathyroid

hyperplasia, pancreatic islet cell tumors, and pituitary adenomas. ME+ a

consists of medullary carcinoma of the thyroid, pheochromocytoma, and

parathyroid hyperplasia. ME+ & includes medullary carcinoma of the

thyroid, pheochromocytoma, mucosal neuromas, and a distinctive marfanoid

ha&itus. %ogether, these syndromes encompass much of the spectrum ofendocrine neoplasia. ;@. Which of the following signs=symptoms are

pathognomonic of hyperparathyroidism> a. 9athologic fractures of the

metacarpals &. Calcium o8alate nephrolithiasis c. Bypercalcemia causing

mental status changes d. "trophy of %ype ## muscle fi&ers e. *steitis fi&rosa


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cystica "nswer! e Manifestations of hyperparathyroidism are protean, &ut

generally nonspecific and may &e difficult to elicit in the history. %he earliest

complaints are often vague and include muscle weaness, anore8ia, nausea,

constipation, polyuria, and polydipsia. %hese nonspecific symptoms may ormay not cause the patient to see medical attention. Symptomatic patients

generally have evidence of chronic disease involving the idney or the

seleton. (enal complications develop &ecause the hypercalcemia leads to

increased urinary calcium e8cretion and 9%B increases the e8cretion of

phosphate. %hese events predispose to stone formation. +ephrolithiasis

develops in a&out 4A3 of patients. +ephrocalcinosis occurs in ;3 to 1A3 of

patients. %hese are &oth nonspecific for hyperparathyroidism. 9arathyroid

&one disease in its most classic and severe form, osteitis fi&rosa cystica, is

seldom seen. Bowever, ;3 to 1;3 of patients present with significant

symptoms of seletal disease. *nly the seletal disease is pathognomonic.

$one changes include su&periosteal resorption of &one on the radial aspect of

the middle phalan8 of the second or third finger. %ufting of the distal

phalanges, &one cysts of the sull and long &ones, &rownD tumors 0i.e.,

localied proliferations of osteoclasts, and diffuse demineraliation or

granularity are seen as well. "trophy of %ype ## muscle fi&ers, consistent with

a neuropathic and not a myopathic cause, has &een demonstrated in patients

with hyperthyroidism, &ut this too is nonspecific. ;5. %he causes of Cushing

syndrome may include which of the following> a. 9osterior pituitary

adenoma &. "drenal hyperplasia c. Small cell lung carcinoma d.

9heochromocytoma e. "drenal carcinoma "nswer! &, c, e %he varied causes

of cortisol e8cess produce clinical features that are collectively called

Cushing syndrome. %hese include e8ogenous steroid administration, Cushingdisease 0e8cessive "C%B production &y the anterior pituitary gland, usually

from an adenoma, ectopic "C%B production 0small cell lung carcinoma,

adrenal adenoma or carcinoma, micronodular pigmented hyperplasia,

macronodular hyperplasia, and steroid-dependent adrenal hyperplasia.


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9heochromocytoma is characteried &y catecholamine rather than cortisol

e8cess as it arises from the adrenal medulla rather than the adrenal corte8. ?A.

Which of the following are normal systemic effects of glucocorticoids> a.

Enhanced proteolysis &. #ncreased gluconeogenesis c. 'iminished lipolysis d.'ecreased rate of intestinal epithelial replication "nswer! a, &, d %he many

systemic effects of glucocorticoids are related to regulation of intermediary

meta&olism. #n this regard, perhaps the most important action is the effect of

steroids on protein &readown. " direct proteolytic effect of steroids is

suggested &y several lines of evidence. lucocorticoids enhance

gluconeogenesis &y &oth a direct effect on gluconeogenic hepatic enymes

and also &y provision of su&strate for gluconeogenesis &y proteolysis.

lucocorticoid influence leads to the accentuation of lipolysis. %he truncal

o&esity seen in steroid e8cess is related to the predominance of the lipogenic

effect of insulin on truncal adipocytes over the lipolytic effect of

glucocorticoids. %he opposite relation may hold for the receptors in fat of the

e8tremities and would e8plain the comparatively scant fat in these areas with

steroid e8cess. %he most nota&le effect of glucocorticoids in the intestinal

tract is a decrease in the rate of mucosal cell replication. #n addition,

decreased mucosal and pancreatic prostaglandin synthesis occur. %his may

have important implications for the cytoprotective mechanisms in the

stomach. ?1. " 1A-year-old child presents with hypertension, tachycardia,

nervousness and sweating. %he &est initial diagnostic evaluation is which of

the following> a. (adioimmunoassays for norepinephrine and epinephrine in

serum &. Magnetic resonance imaging of the adrenal gland c. M#$ 0141#-

Methaiodo&enylguanidine scintigraphy d. Measurement of catecholamines

and their degradation products in a 2-hour urine specimen "nswer! d %hefirst diagnostic step in determining the functional state of an adrenal gland or

lesion is to screen the urine or plasma for secretory products. *nce

hypersecretion is demonstrated, the specific type of pathology producing a

syndrome must &e determined with the aid of functional tests and relevant


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scanning and imaging. %he most efficient and sensitive means of screening in

a patient suspected of having a pheochromocytoma, 0as indicated here is

measurement of the catecholamines or meta&olic products thereof in the

urine. "lthough 2-hour samples can smooth out the possi&le episodicvariations in catecholamine secretion, shorter sampling periods can &e useful,

especially if corrected for creatinine e8cretion. %iming of the collection is

critical in patients who have only episodic hypertension. )rine collection

should &e started immediately after a suspected attac of hypertension.

/luctuations in plasma catecholamine concentrations are much greater than

those in urinary e8cretion, even in normal su&:ects. 9lasma determinations

are uite sensitive and specific with radioimmunoassays and B9


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administering 1AA mg of hydrocortisone intravenously every ? hours during

the first 2@ hours. Some prefer alternating doses of #M cortisone acetate in

the event that intravenous access is lost. 9rovided that no intervening

complications arise, the doses can &e halved every 2@ to 7 hours. #n patientswho have &een e8posed preoperatively to glucocorticoid e8cess, the

maintenance dose may &e as high as 1AA mg=d for several months. $oth high

doses and normal maintenance of 4; to ;; mg=d can &e given in the form of

oral cortisone acetate as long as relia&le alimentation and a&sorption have

&een achieved. %he pituitary-adrenal a8is remains suppressed for ? to 1

months after operation. Complications in the postoperative period include

wound infection, pancreatitis, and throm&oem&olism. %here is no data to

suggest that the ris of postoperative pancreatitis can &e diminished with

somatostatin analogue therapy. ?4. #maging of the adrenal gland is &est

achieved with which of the following techniues> a. )ltrasound &. Computed

tomography 0C% c. "rteriography d. Scintigraphy with 141#-? &-iodomethyl-

15-norcholesterol 0+9-;5 e. Scintigraphy with 141#-

methaiodo&enylguanidine 0M#$ "nswer! & "lthough ultrasonography is

the least e8pensive

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