Title Hologic Proprietary © 2013 ThinPrep ® Non-Gyn Lecture Series Thyroid Cytology.

TitleTitle

Hologic Proprietary © 2013

ThinPrep® Non-Gyn Lecture Series

Thyroid Cytology


Benefits of ThinPrep® Technology

The use of ThinPrep Non-Gyn for Fine Needle Aspiration specimens from the Thyroid:

• Optimizes cell preservation• Standardizes specimen preparation• Simplifies slide screening• Minimize number of slides per patient• Offers the versatility to perform ancillary

testing


Required Materials

• ThinPrep® 2000 Processor or ThinPrep 5000 Processor

• ThinPrep Microscope Slides

• ThinPrep Non-Gyn Filters (Blue)

• Multi-Mix™ Racked Vortexor

• CytoLyt® and PreservCyt® Solutions


Required Materials

• 50 ml capacity swing arm centrifuge • 50 ml centrifuge tubes• Slide staining system and reagents • 1 ml plastic transfer pipettes• 95% alcohol• Coverslips and mounting media

Optional: Glacial acetic acid, DTT and saline for troubleshooting


Recommended Collection Media

• CytoLyt®

• Balanced electrolyte solutions; such as

-Plasma-Lyte®

-Polysol®


Non-Recommended Collection Media

• Sacomanno and other solutions containing carbowax

• Alcohol

• Mucollexx®

• Culture Media, RPMI Solution

• PBS

• Solutions containing formalin


Hologic® Solutions

• CytoLyt®

• PreservCyt®

Copyright © 2013Hologic, All rights reservedCopyright © 2013Hologic, All rights reserved..

Copyright © 2012 Hologic, All rights reserved.Copyright © 2012 Hologic, All rights reserved.


Hologic® SolutionsCytoLyt® Solution

• Methanol-based, buffered preservative solution

- Lyses red blood cells

- Prevents protein precipitation

- Dissolves mucus

- Preserves morphology for 8 days8 days at room temperature

• Intended as transport medium• Used in specimen preparation prior to

processing


Hologic® SolutionsPreservCyt® Solution

• Methanol based, buffered solution• Specimens must be added to PreservCyt

Solution prior to processing • PreservCyt Solution cannot be substituted

with any other reagents• Cells in PreservCyt Solution are preserved

for up to 3 weeks 3 weeks in a temperature range between 4°-37°C


FNA Biopsy

• Performed by a cytopathologist or clinician.

• A 23 gauge or 25 gauge needle with a 10ml syringe is used

• After the area is cleaned with 95% ethanol, the nodule is palpated and held in place with the index and middle fingers

• The needle is passed thru the skin and into the nodule. Several strokes are made with or without vacuum created by the syringe plunger


Sample Collection

• Optimal: Deposit and rinse the entire sample into a centrifuge tube containing 30 ml of CytoLyt® solution

• Secondary method: Collect into a balanced electrolyte solution, such as Polysol® or Plasma-Lyte® injection solutions

• If direct or air dried slides are desired, prepare prior to rinsing the needle

Note: If possible, flush the needle and syringe with a sterile anticoagulant solution prior to aspirating the sample. Some anticoagulants may interfere with other cell processing techniques, so use caution if you plan to use the specimen for other testing.


Sample Preparation

1. Collection

2. Concentrate by centrifugation - 600g for 10 minutes

3. Pour off supernatant and vortex to re-suspend cell pellet

4. Evaluate cell pellet • If cell pellet is not free of blood, add 30 ml of CytoLyt®

Solution to cell pellet and repeat from step 2

5. Add recommended # of drops of specimen to PreservCyt® Solution Vial

6. Allow to stand for 15 minutes

7. Run on ThinPrep® 2000 Processor using Sequence 3 or ThinPrep 5000 using Sequence Non-Gyn

8. Fix, Stain, and Evaluate


Sample Preparation Techniques

• Centrifugation - 600g for 10 minutes or 1200g for 5 minutes

- Concentrates the cellular material in order to separate the cellular components from the supernatant

Refer to Centrifuge Speed Chart in the ThinPrep® 2000 or ThinPrep 5000 Processor Manual, Non-Gynecologic section, to determine the correct speed for your centrifuge to obtain force of 600g or 1200g



• Pour off supernatant- Invert the centrifuge tube 180° in one smooth movement, pour off all supernatant and return tube to its original position

(Note: Failure to completely pour off the supernatant may result in a sparsely cellular sample due to dilution of the cell pellet).



• Vortex to re-suspend cell pellet

- Randomizes the cell pellet and improves

the results of the CytoLyt® solution washing procedure

- Place the centrifuge tube onto a vortexor and agitate the cell pellet for 3 seconds or vortex manually by syringing the pellet back and forth with a plastic pipette



• CytoLyt® Solution Wash- Preserve cellular morphology while lysing red blood cells, dissolving mucus and reducing protein precipitation

- Add 30 ml of CytoLyt Solution to cell pellet, concentrate by centrifugation, pour off the supernatant and vortex to resuspend the cell pellet



• Evaluate cell pellet- If cell pellet is white, pale pink, tan or not

visible add specimen to PreservCyt® Solution vial (# of drops added is dependant on sample volume and will be discussed on future slides)

- If cell pellet is distinctly red or brown indicating the presence of blood conduct a CytoLyt® wash



• Calculate how many drops of specimen to add to PreservCyt® vial:- If pellet is clearly visible and the pellet volume is ≤ 1ml (if not consider the next 2 slides)

• Vortex pellet and transfer 2 drops to a fresh PreservCyt Solution vial



• Calculate how many drops of specimen to add to PreservCyt® vial:

- If pellet volume is ≥1ml • Add 1ml of CytoLyt® Solution into the tube

and vortex briefly to resuspend the cell pellet• Transfer 1 drop of the specimen to a fresh

PreservCyt Solution vial



• Calculate how many drops of specimen to add to PreservCyt® vial:

- If pellet is not visible or scant• Add contents of a fresh PreservCyt Solution

vial into the tube and vortex briefly to mix the solution

• Pour entire sample back into the vial


Sample Preparation Troubleshooting

• Due to the biological variability among samples and variability in collection methods, standard processing may yield a slide that indicates further troubleshooting may be needed.


Sample Preparation Troubleshooting

• After staining, you may observe the following irregularities:• Non-uniform distribution of cells in the cell spot

without a “sample is dilute” message• Uneven distribution in the form of a ring or halo

of cellular material and/or white blood cells• A sparse cell spot lacking in cellular component

and containing blood, protein and debris – may

be accompanied by a “sample is dilute” message


Techniques Used in Troubleshooting

• Diluting the Sample 20 to 1• Glacial Acetic Acid Wash for Blood and Non-

Cellular Debris• Saline Wash for Protein



• Diluting the Sample 20 to 1

- Add 1ml of the sample that is suspended in PreservCyt® Solution to a new PreservCyt Solution vial (20ml). This is most accurately done with a calibrated pipette.



• Glacial Acetic Acid Wash for Blood and Non-Cellular Debris

- If sample is bloody, it can be further washed using a solution of 9 parts CytoLyt® Solution and 1 part Glacial Acetic acid.



• Saline Wash for Protein

- If sample contains protein, it can be further washed with saline solution in place of CytoLyt® Solution.


TroubleshootingBloody or Proteinaceous Specimens

“Sample is Dilute” message

No, continue to next slide

Yes

Check to see if cellularity is adequate. If not, use more of the pellet, if available and prepare new slide.



Does the slide have a “halo” of cellular

material and/or white blood cells?

No, continue to next slide

Yes

Dilute the sample 20:1 by adding 1ml of residual sample to a new PreservCyt® Solution vial and prepare new slide.

If halo is present on the new slide, contact Hologic® Technical Service.



Is the slide sparse and does it contain blood, protein or

non-cellular debris?

Yes-protein

Centrifuge remaining specimen from PreservCyt vial, pour off. Add 30 ml of saline to sample, centrifuge, pour off and vortex. Add to PreservCyt vial and prepare new slide. If resulting slide is sparse, contact Hologic Technical Service.

No

Contact Hologic® Technical Service

Yes-blood or non-cellular debris

Centrifuge remaining specimen from PreservCyt® vial, pour off. Add 30ml of a 9:1 CytoLyt® to glacial acetic acid solution to the sample, centrifuge, pour off and vortex. Add to PreservCyt vial and prepare new slide. If the resulting slide is sparse, contact Hologic Technical Service.


TroubleshootingCommon Artifacts

• Smudged Nuclear Detail

• Compression Artifact

• Staining Artifact

• Edge of the Cylinder Artifact



• Smudged Nuclear Detail• May occur if specimen is collected in saline,

PBS or RPMI• To avoid this, collect the sample either

fresh, in CytoLyt® or in PreservCyt® solution



• Compression Artifact• Appears as “air dry” artifact on the perimeter

of the cell spot• Due to the compression of cells between

the edge of the filter and the glass of the slide



• Staining Artifact• Mimics air-drying• Appears as a red or orange central staining primarily in

cell clusters or groups• Due to the incomplete rinsing of counterstains.• To eliminate this artifact, fresh alcohol baths

or an additional rinse step after the

cytoplasmic stains is required



• Edge of the Cylinder Artifact• Narrow rim of cellular material just beyond

the circumference of the cell spot• Result of cells from the outer edge of the

wet filter cylinder being transferred to

the glass slide


Endocrine GlandsThyroid and Parathyroid Glands1. Cartilage

2. Parathyroid glands-Posterior

6. Right & Left Lobes-Posterior3. Left Lobe

4. Isthmus

5. Right Lobe

LifeART Collection Images Copyright © 1989-2001 by Lippincott Williams & Wilkins, Baltimore, MD

Anatomy


Histology of the Epithelium

• The Thyroid is lined by one type of epithelium:• A single layer of

thyroid epithelial cells called follicular cells that are arranged in spherical follicles arranged around a central ball of colloid

Courtesy of Prof. I. Salmon at Forpath vzw/asbl, oct; 1999


Specimen Adequacy

• Both the quantity and quality of the cellular component as well as colloid must be considered

• Guidelines for specimen adequacy vary. The following is commonly used. A minimum of six groups of well-visualized follicular cells, with at least ten cells per group– Note the following exceptions (Specimens with abundant thick

colloid and solid nodules containing cytologic atypia or consisting only of abundant inflammatory cells should be considered to be benign and satisfactory)


Normal Components and Findings

• Follicular Cells– Range in shape from cuboidal to columnar– Nuclei are round to oval and are about the size

of a lymphocyte– Evenly distributed granular chromatin– Single, in honeycomb sheets and intact follicles

with even spacing– Cytoplasm is fine and pale, stains blue with Pap

stain and blue/purple with Romanowsky stain



• Hürthle Cells– Polygonal in shape and frequently bi-

nucleate– Eccentrically placed nuclei ranging from

small to large – Finely granular, abundant cytoplasm

staining blue to orange in Pap stain and purple in Romanowsky stain



• Flame Cells– Cytoplasm is abundant and

vacuolated-with Romanowsky stain these vacuoles show red to pink staining material which is darker at the edges



• Multinucleated giant cells– Commonly found with papillary carcinoma but not limited to only this

lesion

– Can be found in other benign and malignant conditions

• Lymphocytes– May be present in both benign and malignant lesions

– Can be confused with stripped nuclei of follicular cells

– Will have coarser chromatin, a thin rim of cytoplasm, a less prominent nuclear membrane and the presence of lymphoglandular bodies

• Spindle Cells and Squamous Cells– May be present in both benign and malignant lesions



• Other findings– Hemosiderin

• Associated with bleeding

• Present in aspirations of cyst and can help to favor a benign thyroid nodule over a follicular neoplasm

• Stains golden brown with Pap stain and dark blue in Romanowsky stain

– Calcification• Dystrophic – Can be outline-like or coarse dense nodular

calcifications and can be found in both cysts as well as follicular neoplasm

• Psammomatous – Concentrically laminated crystalline structures associated with Papillary Carcinoma



• Other Findings– Mucin

• When present it’s thought that the aspirated lesion is likely not located in the thyroid, however it may also be associated with all types of thyroid cancers

– Amyloid• Looks similar to dense colloid with a waxy

appearance

• Can be distinguished with Congo red stain

• Is associated with medullary carcinoma but can also be present in amyloid goiter



• Colloid– A honey like, gelatinous secretion that acts as a storage site for

thyroglobulin– An active thyroid will produce a paler, thinner colloid. When less active,

the colloid with tend to be thicker and denser – Stains blue, green, pink or orange with Pap stain and dark blue/purple

with Romanowsky stains• Dense/solid

– Irregularly shaped rounded droplets– Chicken wire appearance– Often shows “stained glass cracking”

• Watery/diffuse– Thin membrane/cellophane /tissue paper like appearance– Cracked /mosaic pattern– Must be distinguished from serum– Can be lost on liquid-based cytology



• Possible Contaminants– Ciliated cells from thyroglossal duct cysts or by

accidental sampling of the trachea– Transgressing blood vessels can be seen and are

sometimes present with Hürthle Cell Neoplasm– Fat although rare may be present from the

subcutaneous adipose tissue in the neck and can also rarely occur a range of thyroid lesions

– Skeletal Muscle will need to be distinguished from dense colloid and will have striations and nuclei


Nondiagnostic Findings

• Cyst fluid only

• Obscuring factors

• Virtually acellular

– Exceptions - Specimens consisting primarily of abundant thick colloid and solid nodules containing cytologic atypia or consisting only of numerous inflammatory cells should be considered to be benign and satisfactory



• Cyst– 15-25% of all thyroid nodules are cystic– Exclusion of malignancy is not possible with

a diagnosis of cyst– Benign and malignant thyroid lesions can be

cystic, Papillary carcinoma being the most common cystic thyroid cancer

– Need to be wary of both false negative and false positive diagnosis



• Cyst– Abundant hemosiderin-laden macrophages– Foamy histiocytes– Blood– Proteinaceous debris– Watery colloid-amount will vary and be difficult to

appreciate– Rare follicular cells may be present

• May show reactive/degenerative changes that can mimic cancer


• Acute Thyroiditis• Granulomatous Thyroiditis

– (Subacute, de Quervain’s)– Fungal

• Aspergillus, Blastomyces, Candida, Pneumocystis

– Parasitic• Echinococcus, Wucheria, Treponema

– Mycobacterial Thyroiditis• Tuberculosis

• Chronic Thyroiditis– Lymphocytic Thyroiditis (Hashimoto)– Riedel Thyroiditis/Disease

Benign Findings


Benign Findings

• Acute Thyroiditis– Very painful, potentially life threatening condition – Very rare due to the accumulation of iodine in the thyroid

that acts as a “germ killer”– Those at risk are the young, old, immunosuppressed and

malnourished– Most common cause is bacterial and less likely fungal– Staphylococcus aureus, Streptococcus pyogenes and

Streptococcus pneumoniae are responsible for approximately 80% of cases

– Typically not aspirated, however if performed, aspiration is a characteristic yellow-green pus


Benign Findings

• Acute Thyroiditis– Abundant neutrophils and histiocytes– Granulations tissue, necrosis and debris– Scant epithelial cells, but when present

may have reactive/degenerative changes– Bacteria may be noted


Benign Findings

• Granulomatous Thyroiditis (Subacute, de Quervain’s)– Commonly diagnosed clinically– Most common cause of painful thyroid disease

and mainly affects middle aged women– Possible viral etiology and may be a genetic

predisposition– Primarily a self-limiting disease for most with

recovery in a few months using nonsteroidal anti-inflammatory treatment


Benign Findings

• Granulomatous Thyroiditis (Subacute, de Quervain’s)– Typically hypocellular– Tell tale multinucleated giant cells that are

engulfing colloid– Loose clusters of epithelioid histiocytes – Scant follicular cells which may show reactive

changes– Background of lymphocytes, plasma cells,

eosinophils and neutrophils


Benign Findings

• Chronic Thyroiditis (Lymphocytic Thyroiditis - Hashimoto)

• Most commonly seen form of thyroiditis• Must be distinguished from MALT lymphoma• Autoimmune disease most common in middle

aged women and adolescents• Many patients don’t need to be aspirated and

can be diagnosed clinically, however approximately one third of patients have atypical presentation and will be biopsied


Benign Findings

• Chronic Thyroiditis (Lymphocytic Thyroiditis - Hashimoto)

• Hypercellular aspirates• Polymorphic lymphoid cells consisting of small

mature lymphocytes, larger reactive lymphoid cells and occasional plasma cells

• Hürthle cells arranged in single cells and sheets

Note: There is no minimum requirement for follicular or Hürthle cell component to be considered satisfactory


• Chronic Thyroiditis (Riedel Thyroiditis)– Unknown origin affecting primarily middle aged

to older women, many of which have a history of Hashimoto thyroiditis

– Most rare of all types of thyroiditis– Epstein-barr virus could be a causative agent– Patient presents with a painless, non-tender

thyroid

Benign Findings


Benign Findings

• Chronic Thyroiditis (Riedel Thyroiditis)– Frequently hypocellular to acellular– Spindle mesenchymal cells– Collagen strands– May be a few lymphocytes, plasma cells,

neutrophils, eosinophils and rare giant cells


Benign Findings

• Black Thyroid– Associated with the antibiotic in the

tetracycline family given for acne treatment called minocycline

– Stains similarly to that of melanin, but is a break down product of the minocycline

– Coarse dark brown/black pigment in the cytoplasm of macrophages, follicular cells and colloid


Benign Findings

• Benign Follicular Nodule-(BFN) Overview– Variable amounts of colloid– Benign appearing follicular cells– Hürthle cells– MacrophagesNote: There may be rare microfollicles

present, but should be out numbered by macrofollicles


Benign Findings

• Benign Follicular Nodule– Nodular goiter– Colloid nodule– Hyperplasic (adenomatoid) nodule– Follicular adenomas (macrofollicular

type) – Grave’s disease


Benign Findings

• While this group of benign lesions have different histological presentations, it is difficult to distinguish them with FNA

• A diagnosis of BFN will warrant the same conservative treatment regardless of which specific histologic type of nodule

• A further sub-classification of type of nodule may be used when possible in addition to the diagnosis of BFN


Benign Findings

• Nodular Goiter– Most commonly seen lesion in thyroid

FNA– Can be distinguished from a follicular

neoplasm by the lack of microfollicles and instead the follicular cells will be arranged in sheets and macrofollicles


Benign Findings

• Nodular Goiter– Scant to moderate cellularity– Abundant colloid– Pigment laden or foamy histiocytes– Follicular cells are arranged in large flat honeycomb

sheets and in macrofollicles– Nuclei of the follicular cells will be spaced uniformly

with in the sheet, centrally placed with in the cytoplasm, small, round and bland appearing

– Naked nuclei may be in the background with in colloid– Scattered Hürthle cells


Benign Findings

• Colloid Nodule– Type of nodular goiter that occurs

when follicular cells respond to the extra release of TSH by the pituitary gland by releasing and storing excess colloid

– Little risk of malignancy– However, a small malignant nodule

could be present next to the sampled colloid nodule


Benign Findings

• Colloid Nodule– Predominantly or consisting only of

abundant colloid– Minimal cellularity - very few or no

follicular cells present

Note: Be sure to distinguish colloid from serum


Benign Findings

• Hyperplastic (adenomatoid) Nodule– Type of nodular goiter that occurs

when follicular cells respond to the extra release of TSH by the pituitary gland by excessive growth


Benign Findings

• Hyperplastic (adenomatoid) Nodule– Moderate cellularity– Scant dense and watery colloid

(there may be a loss of watery colloid on LBC and when present may appear tissue paper like)

– Macrofollicles arranged in honeycomb pattern


Benign Findings

• Follicular Adenoma (macrofollicular type)– Most common thyroid neoplasm– Almost always occurs as a solitary nodule

while the remaining gland is normal


Benign Findings

• Follicular Adenoma (macrofollicular type)– Can have variable cellularity– Follicular cells will display benign features

however the nuclei can be enlarged, coarse and hyperchromatic. The cytoplasm will be finely granular and vacuolated

– Hürthle cells can be present– Flame cell changes may be observed


• Grave’s Disease• Autoimmune disorder• Mainly affects middle aged women• Commonly diagnosed clinically due to hyperthyroidism• Diffuse rather than nodular enlargement in the majority of

patients• FNA is not frequently performed• Considered to be a risk factor for aggressive thyroid

cancer particularly when the nodule is cold with papillary carcinoma being the most common

• The drugs given to treat this disease may cause changes that can be confused with malignancy

Benign Findings


• Grave’s Disease• Cellular aspirate

• Abundant pale watery colloid

• Follicular cells – Variable number

– Large flat sheets and rarely microfollicles

– Abundant, foamy cytoplasm

– Enlarged vesicular nuclei with frequent with anisonucleosis and prominent nucleoli

– Infrequently chromatin clearing and intranuclear grooves can be seen which can be confused with papillary carcinoma

• If the patient has been treated, atypical features of the follicular cells can be significant and confused with malignancy

• Lymphocytes (usually T cells) and oncocytes

• Flame cells

Benign Findings


Atypical Findings

• Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance

• The degree of atypia associated with this category is not severe enough to warrant a suspicious diagnosis and is felt to be caused by a benign process and/or the cellularity while adequate for diagnosis, may be less than desirable

• Clinical correlation and repeat FNA is the recommended follow up treatment


• Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance-possible uses• Predominance of microfollicles or Hürthle cells in a sparsely cellular

sample

• Abundant Hürthle cells in either a patient with known Hashimoto thyroiditis or in a patient with multinodular goiter

• Air drying that causes poor nuclear detail, cyst lining cells that are less elongated and more tightly packed and rare nuclear enlargement with prominent nucleoli, all can mimic papillary carcinoma

• Artificial crowding of follicular cells due to abundant blood and clotting may mimic a follicular neoplasm

• Rare cells with mild atypia sometimes present in Hashimoto thyroiditis

• An atypical lymphoid infiltrate (flow cytometry needed)

Atypical Findings


• Suspicious for a Follicular Neoplasm• Follicular carcinoma is the second most common malignancy

in the thyroid• If well differentiated will have a good prognosis• Difficult to distinguish between a benign follicular lesion and a

carcinoma on FNA• Many FNA’s given this diagnosis will ultimately turn out to be

a benign proliferation• FNA has shown to have a high sensitivity but low specificity

for follicular carcinoma and therefore considered a screening test rather than a diagnostic test for this diagnosis

• Lobectomy or hemithyroidectomy is the follow up treatment with this category where further histologic classification can be made

Suspicious Findings


Suspicious Findings

• Suspicious for a Follicular Neoplasm• Moderate cellularity with architectural alteration • Cell crowding• Overlapping• Follicular cells with round nuclei are arranged in microfollicles,

single cells and occasional trabeculae• Hyperchromasia, anisonucleosis and prominent nucleoli may

be present• Chromatin may be less granular than benign follicular cells

display and have an open appearance• Little to no colloid• Foamy and hemosiderin laden macrophages may be present if

cystic


Malignant Findings

• Follicular Neoplasm, Hürthle Cell Type– Uncommon subset of follicular neoplasm

composed predominantly of oncocytic cells

– The majority of FNA’s diagnosed as Hürthle cell neoplasm will be adenomas rather than carcinomas


Malignant Findings

• Follicular Neoplasm, Hürthle Cell Type– Polygonal shaped cells arranged in a single cell pattern,

loosely cohesive or crowded three dimensional groups

– Abundant, dense, granular cytoplasm

– Nuclei are round and eccentrically placed with a prominent central nucleoli

– Plasmacytoid appearance

– Occasional binucleation is seen

– Variation in both size of cells and size of nuclei can occur

– Colloid is either scant or absent

– Chronic inflammatory cells are absent


Malignant Findings

• Papillary Carcinoma• Most Common malignancy in the thyroid• Can occur in any age range• More common in women that men• Good prognosis• Flat sheets can mimic benign cells. Nuclear

detail must be examined• Many of the following criteria must be present in

order to make the diagnosis of papillary carcinoma


Malignant Findings

• Papillary Carcinoma• Syncytial flat sheets and papillary groups

– Sometimes in a swirling like pattern

• Increased cellularity with crowding and overlapping

• Nuclei are enlarged, pale, round to oval or irregular in shape and can display grooves and molding

• Chromatin is pale and powdery with micronucleoli

• Intranuclear cytoplasmic inclusions (can also be seen in other thyroid neoplasms)

• Psammoma bodies are rare, but can be seen

• Multinucleated giant cells are often present

• Colloid may be present

• Hürthle cells and hemosiderin laden macrophages can be seen


• Papillary Carcinoma Variants– Variants have the same abnormal

features of papillary carcinoma, but show some architectural, background or cytoplasmic differences

– Some variants may have a different prognosis for the patient

Malignant Findings


• Papillary Carcinoma Variants– Follicular

• Specimen consists of subtle features of papillary carcinoma arranged in small to medium microfollicles

– Cystic• Follicular cells with the features of papillary

carcinoma arranged in small groups, sheets, follicles or papillary arrangements that have abundant, granular or vacuolated cytoplasm in a cystic background of watery colloid and hemosiderin laden macrophages

Malignant Findings


• Papillary Carcinoma Variants– Warthin-like

• Neoplastic cells are arranged in papillary groups, have oncocytic cytoplasm and a background of lymphocytes. When these lymphocytes are admixed with neoplastic cells, be sure the changes represent true malignant features and are not just reactive changes.

– Oncocytic• Abundant oncocytic/granular cytoplasm is the

dominating type of cytoplasm present in the neoplastic cells with an absence of lymphocytes

Malignant Findings


• Papillary Carcinoma Variants– Tall Cell- (Aggressive type)

• At least half of the neoplastic cells are arranged in papillary groups consisting of cells with the features of papillary carcinoma, but are elongated (at least 2-3 times long as wide) with abundant granular cytoplasm with intranuclear cytoplasmic inclusions being more common and often multiple. Occasional lymphocytes may be seen

– Macrofollicular• Subtle nuclear features of papillary carcinoma are found

in macrofollicular sheets that make up at least half of the specimen

Malignant Findings


• Papillary Carcinoma Variants– Columnar Cell (Rare aggressive type)

• Cellular aspirate with elongated, columnar, stratified, crowded cells that are typically arranged in papillary groups, but can be seen in flat sheets or clusters

• Longer in height than the tall cell variant• Nuclei are hyperchromatic, oval and uniform with

discreet nucleoli• Traditional features of papillary carcinoma are not

present

Malignant Findings


• Papillary Carcinoma Variants– Hyalinizing Trabecular

• Difficult to diagnose cytologically• Tight groups of cells with a core of hyaline

stromal material • Many of the same features of papillary

carcinoma including; psammoma bodies, intranuclear cytoplasmic inclusions as well as nuclear grooves

Malignant Findings


Malignant Findings

• Medullary Thyroid Carcinoma• Associated with other neuroendocrine tumors and although less common

than sporadic occurrences, can be hereditary• A mutation in the RET proto-oncogene located at 10q11.2 is responsible

for the hereditary form of this malignancy• Unlike other malignancies in the thyroid, medullary carcinoma arises in

the parafollicular C cells• A combination of a follicular nodule with increased serum calcitonin levels

are findings that are indicative of medullary carcinoma• Congo red stain for amyloid and immunohistochemical stains can aid in

the diagnosis with FNA – Immunohistochemical staining;

» Calcitonin, CEA, chromogranin and synaptophysin positive (however occasionally negative for calcitonin)

» Thyroglobulin negative (however occasionally positive)


Malignant Findings

• Medullary Thyroid Carcinoma• While not necessary to include subtype in

the diagnosis, there are many possible variants which can be difficult to distinguish from other malignancies;

– Small cell, papillary, follicular/glandular, spindle cell, oncocytic, clear cell, giant cell, mixed follicular/medullary(parafollicular), neuroblastoma like, paraganglioma like, angiosarcoma like, melanin producing, amphicrine, squamous cell


Malignant Findings

• Medullary Thyroid Carcinoma• Single, dyshesive cells is the predominant pattern

although clusters, papillae and follicles can be present

• Cells may be many different shapes including round, polygonal, plasmacytoid and spindled

• Amyloid is frequently present and stains red with Congo red stain, but when polarized light is applied changes to apple-green


Malignant Findings

• Medullary Thyroid Carcinoma• Nuclei are commonly binucleated or multinucleated,

eccentrically located and typically round to oval with the exception of the spindle cell variant in which case they will be elongated

• Chromatin is coarsely granular with small nucleoli, but less frequently can be prominent

• Cytoplasm can be variable, but is commonly abundant and finely granular

• Nuclear grooves and nuclear pseudoinclusions may been seen• Cytoplasmic granules stain red with Romanowsky stain, are

present in a large majority of cases, however when present are only in a small portion of cells


Malignant Findings

• Poorly Differentiated Carcinoma• Rare, aggressive malignancy of follicular cell origin with

subtypes that can coexist including:• Insular

• Non-insular

– Can arise as a transformation from a well differentiated carcinoma (papillary or follicular)and then go onto further transform into undifferentiated carcinoma (anaplastic)

– Patients usually present with advanced disease– Lymph node and lung or bone metastasis is common– Difficult to diagnose using FNA and are often called suspicious

for a follicular neoplasm– Immunohistochemical staining;

• Thyroglobulin, TTF-1 and cytokeratin positive

• Calcitonin negative


• Poorly Differentiated Carcinoma– Aspirates are highly cellular– Cells are arranged singly, in crowded groups, papillary-

like aggregates or microfollicles, and can be wrapped by endothelium, creating insulae or trabeculae

– Naked stripped nuclei, necrosis and mitoses are often present

– Cytoplasm is scant and the cells often have a plasmacytoid appearance

– Nuclei are round and frequently display variation in both size and shape with irregular nuclear borders, granular to coarse chromatin and can have varying sizes of nucleoli

Malignant Findings


Malignant Findings

• Undifferentiated Carcinoma (Anaplastic)• Rapidly growing, rare, extremely aggressive tumor• More common in women over age 50 than men • Rapid tumor growth infiltrates into surrounding soft

tissues of the neck as well as cartilage and bone.• Common site for metastasis is the lung• A secondary co-existing thyroid carcinoma may also be

present in some cases • Immunocytochemistry staining results are variable;

– Pan-keratin and vimentin often positive– TTF-1 and thyroglobulin often negative


Malignant Findings

• Undifferentiated Carcinoma (Anaplastic)• Cellularity can vary and be decreased due to dense

fibrotic stroma and necrosis• Cells are commonly arranged in single cells,

crowded groups and stripped nuclei• Cells are round to polygonal or sometimes spindle in

shape with marked variation in size (can be giant)


Malignant Findings

• Undifferentiated Carcinoma (Anaplastic)• Nuclei are enlarged, hyperchromatic, with coarse,

irregular chromatin, irregular nuclear borders, macronucleoli and intranuclear cytoplasmic inclusions

• Abundant inflammatory cells, primarily neutrophils can be present sometimes invading the cytoplasm of tumor cells

• Frequent normal and abnormal mitoses

• Squamous differentiation may be present and should be distinguished from Squamous cell carcinoma


Malignant Findings

• Metastatic Carcinomas and Lymphomas• Metastases are uncommon, however when present, here are some of the most

common;– Kidney- Must be distinguished from a follicular and Hürthle cell neoplasms– Colorectal- Use classic criteria such as columnar shape to diagnose– Lung- Papillary lesions may be confused with papillary thyroid carcinoma and small

cell ca may mimic insular carcinoma– Breast- Must be distinguished from a follicular neoplasm– Melanoma- Must be distinguished from medullary or anaplastic carcinoma– Lymphoma- May be primary or secondary, the latter being more common. Can be

confused with undifferentiated carcinoma or Hashimoto thyroiditis– Squamous cell carcinoma- May be primary or metastatic. Uncommon with a poor

prognosis primarily occurring in the elderly. Can be difficult to distinguish from an undifferentiated carcinoma with squamous differentiation

• Patient history, flow cytometry (when considering a lymphoma) and immunocytochemistry (TTF-1 and thyroglobulin) are invaluable in diagnosing these cases


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All other trademarks are the property of their respective owners.


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• Visit our websites: www.hologic.com, www.thinprep.com, www.cytologystuff.com- Product Catalog- Contact Information- Complete Gynecologic and Non-

gynecologic Bibliographies- Cytology Case Presentations and

Unknowns


Bibliography

ThinPrep® 2000 Processor Operator’s ManualThinPrep 5000 Processor Operator’s ManualAli, Syed Z., Cibas, Edmund J.: The Bethesda System

for Reporting Thyroid Cytopathology Definitions, Criteria and Explanatory Notes, 2010:1-171

Layfield, Lester: Cytopathology of the Head and Neck ASCP Theory and Practice of Cytopathology Series 7, 1997: 159-208

Clark, Douglas P., Faquin, William C.: Thyroid Cytopathology Second Edition, 2010: 1-200

DeMay, Richard M: The Art & Science of Cytopathology 2nd Edition Superficial Aspiration Cytology (Volume 2 of 4), 2012: 839-963


Bibliography

Images:Salmon, I. Prof. Normal Thyroid. Photograph. Forpath

vzw/asbl, oct; 1999[http://www.forpath.org/workshops/9910/images/th02.jpg]

28 December 2012SmartDraw® (Standard Edition) [Software]. (2011).

Retrieved from http://www.smartdraw.comThinPrep® Non-Gyn Morphology Reference Atlas:

Thyroid: 223-244http://www.cytologystuff.com/learn/section2660.htmlhttp://www.cytologystuff.com/learn/section2241.html

Title Hologic Proprietary © 2013 ThinPrep ® Non-Gyn Lecture Series Thyroid Cytology.

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