Imaging TheImaging The Turkish SaddleTurkish Saddle

Russell Goodman, HMS IIIRussell Goodman, HMS IIIDr. Gillian Lieberman Dr. Gillian Lieberman

Learning ObjectivesLearning Objectives

Review the anatomy of the sellar regionReview the anatomy of the sellar region

Discuss the differential diagnosis of sellar massesDiscuss the differential diagnosis of sellar masses

Discuss typical clinical presentations of sellar Discuss typical clinical presentations of sellar massesmasses

Review the menu of radiologic tests available for Review the menu of radiologic tests available for imaging sellar massesimaging sellar masses

Demonstrate the radiologic features of a number of Demonstrate the radiologic features of a number of different sellar massesdifferent sellar masses

Anatomy of the Sella Turcica Anatomy of the Sella Turcica

The sella turcica, literally The sella turcica, literally ““Turkish Turkish saddlesaddle””, is a saddle, is a saddle--shaped depression shaped depression of the sphenoid bone of the sphenoid bone

It forms the caudal border of the It forms the caudal border of the pituitary glandpituitary gland

Anatomically complex area, with a Anatomically complex area, with a number of different potential number of different potential pathologies, especially neoplastic pathologies, especially neoplastic processesprocesses

Pathologies can can lead to important Pathologies can can lead to important clinical presentations, such as clinical presentations, such as hormonal imbalances (from hormonal imbalances (from pathologies affecting the pituitary pathologies affecting the pituitary gland) and neurological symptomsgland) and neurological symptoms

.

From Grey’s Anatomy

From http://www.easttexassaddle.com//

Sellar Anatomy (Coronal)Sellar Anatomy (Coronal)

PACS, BIDMC

Modified from Access Medicine

1.

Optic Chiasm2.

Pituitary Gland3.

Internal carotids4.

Cavernous sinus andcranial nerves

5.

Sphenoid sinuses

Coronal MRI, T1 C-

Normal

Sellar Anatomy (Coronal)Sellar Anatomy (Coronal)

1.

Optic Chiasm 2.

Pituitary Gland3.

Internal carotids4.

Cavernous sinus andcranial nerves

5.

Sphenoid sinuses

Coronal MRI, T1 C-

Differential Diagnosis of Differential Diagnosis of SellarSellar

MassesMasses

Differential diagnosis is large!Differential diagnosis is large!

Neoplastic processesNeoplastic processes

Pituitary adenomaPituitary adenoma

MeningiomaMeningioma

CraniopharyngiomaCraniopharyngioma

Germ cell tumorGerm cell tumor

Metastatic diseaseMetastatic disease

Cystic LesionsCystic Lesions

RathkeRathke’’s cleft cysts cleft cyst

Arachnoid cystArachnoid cyst

Dermoid/Epidermoid cystDermoid/Epidermoid cyst

Infectious and inflammatory lesionsInfectious and inflammatory lesions

Pituitary abscessPituitary abscess

Lymphocytic hypophysitisLymphocytic hypophysitis

Granulomatous hypophysitisGranulomatous hypophysitis

Other massesOther masses

AneurysmsAneurysms

Pituitary hematomaPituitary hematoma

Pituitary hyperplasiaPituitary hyperplasia

Presentation of Sellar MassesPresentation of Sellar Masses

Three common presentations:Three common presentations:

1. Incidental finding1. Incidental finding

Huge number of head images taken each yearHuge number of head images taken each year

Autopsy series demonstrate that asymptomatic pituitary Autopsy series demonstrate that asymptomatic pituitary microadenomas are present in as high as 27% of autopsy seriesmicroadenomas are present in as high as 27% of autopsy series

2. Hormonal Imbalances2. Hormonal Imbalances

Pituitary gland is responsible for much of the bodyPituitary gland is responsible for much of the body’’s hormonal s hormonal regulation. regulation.

In principle can have excess production of any of the hormones iIn principle can have excess production of any of the hormones in n the anterior pituitary (Prolactin, GH, ACTH, TSH, FSH/LH) from athe anterior pituitary (Prolactin, GH, ACTH, TSH, FSH/LH) from a

pituitary adenomapituitary adenoma

Prolactin (most common), ACTH (cushingoid), GH (acromegaly),Prolactin (most common), ACTH (cushingoid), GH (acromegaly),

Decreased production: usually from mass effect on pituitary glanDecreased production: usually from mass effect on pituitary glandd

3. Neurological symptoms3. Neurological symptoms

Headache from mass effect, cranial nerve symptoms from Headache from mass effect, cranial nerve symptoms from compression, visual disturbances (classically bitemporal hemianocompression, visual disturbances (classically bitemporal hemianopsia) psia) from compression of optic chiasmfrom compression of optic chiasm

Menu of Radiologic TestsMenu of Radiologic Tests

2 most common methods of imaging:2 most common methods of imaging:

Head CTHead CT

Excellent imaging of bony structures, particularly Excellent imaging of bony structures, particularly useful in preparing for surgical resection of sellar useful in preparing for surgical resection of sellar massesmasses

Also good at demonstrating calcifications (present in Also good at demonstrating calcifications (present in certain masses)certain masses)

Poor soft tissue resolutionPoor soft tissue resolution

Ionizing radiationIonizing radiation

MRIMRI

Superb softSuperb soft--tissue resolutiontissue resolution

Workhorse of pituitary imagingWorkhorse of pituitary imaging

No ionizing radiationNo ionizing radiation

Our PatientOur Patient…… HistoryHistory

A. N. , a 47 y/o local Boston manA. N. , a 47 y/o local Boston man

HPI: HPI:

Presented to his PCP for f/u of abnormal laboratory values. 2 wPresented to his PCP for f/u of abnormal laboratory values. 2 weeks eeks prior he had been treated at OSH ED for acute abdominal pain andprior he had been treated at OSH ED for acute abdominal pain and

vomiting. He had been diagnosed with a duodenal ulcer and dischavomiting. He had been diagnosed with a duodenal ulcer and discharged on rged on highhigh--dose PPIs, but encouraged to f/u for high levels of blood calciudose PPIs, but encouraged to f/u for high levels of blood calciumm

At PCP, ROS endorsed headaches, decreased libido At PCP, ROS endorsed headaches, decreased libido

PMH: PMH:

Duodenal ulcerDuodenal ulcer

HypertensionHypertension

DyslipidemiaDyslipidemia

Chronic diarrheaChronic diarrhea

FMH: FMH:

Strong family history of MEN1 in mother and maternal uncleStrong family history of MEN1 in mother and maternal uncle

Lab values notable for elevated calcium, Lab values notable for elevated calcium, prolactin levels.prolactin levels.

Given his family history of MEN1 and Given his family history of MEN1 and current problems, what are you concerned current problems, what are you concerned about?about?

MEN1 typically presents with neoplastic MEN1 typically presents with neoplastic processes in the pituitary gland, parathyroid processes in the pituitary gland, parathyroid gland, and pancreasgland, and pancreas

(3 midline Ps)(3 midline Ps)

He was scheduled for a number of imaging He was scheduled for a number of imaging studies, which included a brain CT and studies, which included a brain CT and MRI to look for a pituitary adenomaMRI to look for a pituitary adenoma

Imaging demonstrates the classic features Imaging demonstrates the classic features of a pituitary macroadenomaof a pituitary macroadenoma

Our PatientOur Patient…… HistoryHistory

From endocrine.niddk.nih.gov

Our PatientOur Patient…… CTCT

Characteristic features of pituitary Characteristic features of pituitary macroadenomamacroadenoma

1) Remodeling of sellar floor 1) Remodeling of sellar floor (scalloping, erosions, increased size) (scalloping, erosions, increased size) --> > Best seen on CTBest seen on CT

2) Large intrasellar mass > 1 cm in 2) Large intrasellar mass > 1 cm in diameter) which extends beyond diameter) which extends beyond boundaries of sella turcica, often with boundaries of sella turcica, often with ““snowman appearancesnowman appearance””

3) Hypointense3) Hypointense--isointense on T1isointense on T1

4) Enhance slightly with contrast, often 4) Enhance slightly with contrast, often heterogeneously heterogeneously

PACS, BIDMC

Sella

Turcica, displaying increased size

andscalloping of wall.

Sagittal

Head CT, C-

Our PatientOur Patient…… CTCT

Sagittal

Head CT, C-Sella

Turcica, displaying normal size

PACS, BIDMC

Sella

Turcica, displaying increased size

andscalloping of wall.

Sagittal

Head CT, C-

Our PatientOur Patient…… MRMR

Characteristic features of pituitary Characteristic features of pituitary macroadenomamacroadenoma

1) Remodeling of Sellar Floor 1) Remodeling of Sellar Floor (scalloping, erosions, increased size) (scalloping, erosions, increased size) --> > Best seen on CTBest seen on CT

2) Large intrasellar mass (> 1 cm in 2) Large intrasellar mass (> 1 cm in diameter) which extends beyond diameter) which extends beyond boundaries of sella turcica, often with boundaries of sella turcica, often with ““snowman appearancesnowman appearance””

3) Hypointense3) Hypointense--isointense on T1isointense on T1

4) Enhance slightly with contrast, often 4) Enhance slightly with contrast, often heterogeneously heterogeneously

Sagittal

Head MRI, T1 C-, showing a pituitary mass.

Our PatientOur Patient…… MRMR

Characteristic features of pituitary Characteristic features of pituitary macroadenomamacroadenoma

1) Remodeling of Sellar Floor 1) Remodeling of Sellar Floor (scalloping, erosions, increased size) (scalloping, erosions, increased size) --> > Best seen on CTBest seen on CT

2) Large intrasellar mass (> 1 cm in 2) Large intrasellar mass (> 1 cm in diameter) which extends beyond diameter) which extends beyond boundaries of sella turcica, often with boundaries of sella turcica, often with ““snowman appearancesnowman appearance””

3) Hypointense3) Hypointense--isointense on T1isointense on T1

4) Enhance slightly with contrast, often 4) Enhance slightly with contrast, often heterogeneously heterogeneously

Sagittal

Head MRI, T1 C+, showing a pituitary mass.

Medical therapy for prolactinoma Medical therapy for prolactinoma (bromocriptine) was tried and failed(bromocriptine) was tried and failed

Transphenoidal resection of tumor was Transphenoidal resection of tumor was conductedconducted

Multiple other operations to remove other Multiple other operations to remove other MEN neoplasias, including parathyroid MEN neoplasias, including parathyroid adenomas and adenomas and gastrinomagastrinoma

Closely followed by endocrinology and GIClosely followed by endocrinology and GI

Our PatientOur Patient…… Clinical Clinical FollowupFollowup

After

Before

Sagittal

Head MRI, T1 C+, showing a pituitary mass.

Sagittal

Head MRI, T1 C+, showing a resected

pituitary mass.

Companion Patient #1Companion Patient #1…… MacroadenomaMacroadenoma

47 y/o Female who presented to her 47 y/o Female who presented to her PCP with progressive temporal visual PCP with progressive temporal visual field cuts and galactorrheafield cuts and galactorrhea

ProlactinProlactin--secreting Macroadenomasecreting Macroadenoma

Macroadenomas can present with visual Macroadenomas can present with visual changes due to compression of the optic changes due to compression of the optic chiasm chiasm

Classically this is in the form of Classically this is in the form of bitemporal hemianopsiabitemporal hemianopsia

Coronal Head MRI, T1 C-, showing compression of theoptic chiasm

by a large pituitary mass.

Companion Patient #1Companion Patient #1…… ““Snowman SignSnowman Sign””

Coronal Head MRI, T1 C-, showing the “Snowman Sign”.

Pituitary apoplexy is a complication of Pituitary apoplexy is a complication of macroadenomas that occurs when they grow too macroadenomas that occurs when they grow too large for their blood supply and infarct, or large for their blood supply and infarct, or spontaneously bleedsspontaneously bleeds

This is SheehanThis is Sheehan’’s syndrome when it occurs s syndrome when it occurs postpartum due to hormonally driven pituitary postpartum due to hormonally driven pituitary enlargement in pregnant womenenlargement in pregnant women

This results in a sudden change in tumor size from This results in a sudden change in tumor size from either ischemiaeither ischemia--related swelling or acute related swelling or acute hemorrhagehemorrhage

Often associated with acute neurological symptoms Often associated with acute neurological symptoms such as nausea, headache, sudden visual loss such as nausea, headache, sudden visual loss

Classical features are a hemorrhagic fluid level, Classical features are a hemorrhagic fluid level, demonstrated nicely on this image.demonstrated nicely on this image.

Companion Patient #2Companion Patient #2…… Pituitary ApoplexyPituitary Apoplexy

Axial head MRI, T2, from Khan 2009, showing a large pituitary mass

with a hemorrhagic fluid level.

Companion Patient #3Companion Patient #3…… MicroadenomaMicroadenoma

Patient is 81 Patient is 81 y/oy/o

male with male with prolactinomaprolactinoma

Pituitary microadenoma is the most common pituitary Pituitary microadenoma is the most common pituitary pituitary masspituitary mass

Benign neoplastic process of anterior pituitaryBenign neoplastic process of anterior pituitary

Up to 10% of all intracranial Up to 10% of all intracranial neoplasmsneoplasms

Radiologic features includeRadiologic features include

1) Round or oval shape1) Round or oval shape

1) Small size (< 1 cm) which normally preserves anatomy1) Small size (< 1 cm) which normally preserves anatomy

2) Isointense to hypointense on non2) Isointense to hypointense on non--contrast MRIcontrast MRI

3) Hypointense post contrast3) Hypointense post contrast

Location can be a clue to tissue of originLocation can be a clue to tissue of origin

Prolactinoma and GHProlactinoma and GH--secreting are lateralsecreting are lateral

ACTHACTH--secreting tend to be more medialsecreting tend to be more medial

Coronal head MRI T1, C-, with isointense

mass.

Coronal head MRI T1, C+, with hypointense

mass.

Companion Patient #3Companion Patient #3…… MicroadenomaMicroadenoma

Patient is 81 Patient is 81 y/oy/o

male with male with prolactinomaprolactinoma

Pituitary microadenoma is the most common pituitary Pituitary microadenoma is the most common pituitary massmass

Benign neoplastic process of anterior pituitaryBenign neoplastic process of anterior pituitary

Up to 10% of all intracranial Up to 10% of all intracranial neoplasmsneoplasms

Radiologic features includeRadiologic features include

1) Round or oval shape1) Round or oval shape

1) Small size (< 1 cm) which normally preserves anatomy1) Small size (< 1 cm) which normally preserves anatomy

2) Isointense to hypointense on non2) Isointense to hypointense on non--contrast MRIcontrast MRI

3) Hypointense post contrast3) Hypointense post contrast

Location can be a clue to tissue of originLocation can be a clue to tissue of origin

Prolactinoma and GHProlactinoma and GH--secreting are lateralsecreting are lateral

ACTHACTH--secreting tend to be more medialsecreting tend to be more medial

Coronal head MRI T1, C-, with isointense

mass.

Coronal head MRI T1, C+, with hypointense

mass.

Other MassesOther Masses……

WeWe’’ve seen several examples of adenomasve seen several examples of adenomas

Now weNow we’’ll see examples of several other pathologiesll see examples of several other pathologies

Companion Patient #4Companion Patient #4…… CraniopharyngiomaCraniopharyngioma

Images courtesy of Dr. Moonis

Slow growing tumor that Slow growing tumor that arises from epithelium derived arises from epithelium derived from Rathkefrom Rathke’’s pouch s pouch

Abundant calcifications in Abundant calcifications in ~93% of cases~93% of cases

Suprasellar in locationSuprasellar in location

Heterogeneous with cystic Heterogeneous with cystic and solid componentsand solid components

Cyst wall often enhances after Cyst wall often enhances after contrastcontrast

Axial Head CT, C-, showing calcifications

Sagittal

Head MRI T1, C-, showing suprasellar

mass.

Companion Patient #4Companion Patient #4…… CraniopharyngiomaCraniopharyngioma

Images courtesy of Dr. Moonis

Slow growing tumor that Slow growing tumor that arises from epithelium derived arises from epithelium derived from Rathkefrom Rathke’’s pouch s pouch

Abundant calcifications in Abundant calcifications in ~93% of cases~93% of cases

Suprasellar in locationSuprasellar in location

Heterogeneous with cystic Heterogeneous with cystic and solid componentsand solid components

Cyst wall often enhances after Cyst wall often enhances after contrastcontrast

Axial Head CT, C-, showing calcifications

Sagittal

Head MRI T1, C-, showing suprasellar

mass.

Companion Patient #5Companion Patient #5…… RathkeRathke’’ss

Cleft CystCleft Cyst

56 y/o Male with chronic headache56 y/o Male with chronic headache

Benign cyst in the sellar regionBenign cyst in the sellar region

Remnants of derivatives of RathkeRemnants of derivatives of Rathke’’s clefts cleft

Normally asymptomatic, but can cause Normally asymptomatic, but can cause neurological symptomsneurological symptoms

Common finding in autopsy (13Common finding in autopsy (13--22%)22%)

Usually intrasellar, located between Usually intrasellar, located between anterioranterior

and and posteriorposterior

lobeslobes

Hyperintense on T1, intermediate to Hyperintense on T1, intermediate to reduced T2reduced T2--weighted signalweighted signal

Take up contrast less than surrounding Take up contrast less than surrounding tissuetissue

Sagittal

Head MRI, T1 C-, showing cyst, anterior

and posterior

pituitary

Companion Patient #5Companion Patient #5…… RathkeRathke’’ss

Cleft CystCleft Cyst

Sagittal

Head MRI, T1 C-, showing pituitary gland with cyst.

Sagittal

Head MRI, T1 C+, showing pituitary gland with cyst.

Summary and TakeSummary and Take--Home PointsHome Points

The sella turcica is formed by a depression in the sphenoid boneThe sella turcica is formed by a depression in the sphenoid bone

and and

houses the pituitary gland, with many proximal important anatomihouses the pituitary gland, with many proximal important anatomical cal structures.structures.

The differential diagnosis for sellar masses is long, but most fThe differential diagnosis for sellar masses is long, but most frequently requently is a neoplastic process such a pituitary adenomais a neoplastic process such a pituitary adenoma

Masses in the region commonly present with either hormonal Masses in the region commonly present with either hormonal abnormalities or neurologic symptoms, such as vision impairmentabnormalities or neurologic symptoms, such as vision impairment

The superb softThe superb soft--tissue resolution of MRI makes it the imaging method tissue resolution of MRI makes it the imaging method of choice for evaluation of these masses of choice for evaluation of these masses

Provided examples of pituitary microadenoma, macroadenoma, Provided examples of pituitary microadenoma, macroadenoma, craniopharyngioma, Rathkecraniopharyngioma, Rathke’’s cleft cystss cleft cysts

AcknowledgementsAcknowledgements

Thank you to:Thank you to:

Dr. Gillian LiebermanDr. Gillian Lieberman

Maria Levantakis Maria Levantakis

Dr. Gul MoonisDr. Gul Moonis

ReferencesReferences

Conner SEJ and Penny CC. MRI in the Differential Diagnosis of a Conner SEJ and Penny CC. MRI in the Differential Diagnosis of a Sellar Mass. Clin Sellar Mass. Clin 

Radiol 2003 Jan;58(1):20Radiol 2003 Jan;58(1):20‐‐31.31.

Fredua PU and Post KD. Differential Diagonosis of Sellar Masses.Fredua PU and Post KD. Differential Diagonosis of Sellar Masses.

EndocrinolEndocrinol

MetabMetab

ClinClin

North Am 1999 Mar;28(1):81North Am 1999 Mar;28(1):81‐‐117.117.

MolitchMolitch

ME, Russell EJ. The Pituitary ME, Russell EJ. The Pituitary ““IncidentalomaIncidentaloma””. Ann Intern Med 1990 Jun . Ann Intern Med 1990 Jun 

15;112(12);95215;112(12);952‐‐31.31.

RennertRennert

J and J and DoerflerDoerfler

A. Imaging of sellar and A. Imaging of sellar and parasellarparasellar

lesions. lesions. ClinClin

NeurolNeurol

NeurosurgNeurosurg

2007 Feb;109(2):1112007 Feb;109(2):111‐‐24. 24. 

AshrafAshraf

K. Surgical Pathology of Endocrine and K. Surgical Pathology of Endocrine and NeuroendocrineNeuroendocrine

tumors. 2009tumors. 2009