Bethesda Thyroid Cytology Flashcards
Implied Risk of Malignancy of Benign
0-3%
Implied Risk of Malignancy of Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance
5-15%
Implied Risk of Malignancy of Follicular Neoplasm or Suspicious for a Follicular Neoplasm
15-30%
Implied Risk of Malignancy of Suspicious for Malignancy
60-75%
Implied Risk of Malignancy of Malignant
97-99%
Conditions for Satisfactory
If otherwise normal constituents, IE. no abnormal dx can be made:
- 6 groups of 10 follicular cells
- exceptions:solid nodules with inflammation fitting dx for Hashimoto’s, thyroid abscess or granulomatous thyroiditis; colloid nodules
Management for nondx?
Reaspirate no sooner than 3 months later
Criteria for undifferentiated (anaplastic) carcinoma
moderately to markedly cellular
- isolated cells or variable sized groups
- epithelioid (round to polygona) and/or spindle-shaped, ranging from small to giant sized
- plasmacytoid/rhabdoid
- nuclear enlargement, irregularity, pleomorphism, eccentric placement, multinucleation
- clumped chromatin with parahcromatin clearing
- prominent irregular nucleoli
- intranuclear inclusions
- necrosis, extensive inflammation, fibrous connective tissue
- osteoclast-like giant cells, neutrophils
- mitotic figures
Criteria for poorly differentiated thyroid carcinoma
- insular, solid or trabecular cytoarchitecture
- uniform population of follicular cells with scant cytoplasm
- malignant cells have high NC ratio with variable nuclear atypia
- apoptosis and mitotic activity
- necrosis
Criteria for medullary thyroid carcinoma
- numerous isolated cells alternating with syncytial-like clusters in variable proportions from case to case
- plasmacytoid, polygonal, round and/or spindle-shaped
- long cell processes
- mild to moderate pleomorphism
- rare bizarre giant cells
- nuclei round, eccentrically placed, binucleation/multinucleation
- finely or coarsely granular chromatin
- nuclear pseudoinclusions
- nucleoli are usually inconspicuous but can be prominent
- cytoplasm is granular and variable in quantity
- amyloid
Criteria for papillary thyroid carcinoma
- papillae/syncytial-like monolayers/swirling sheets
- enlarged nuclei
- oval or irrgeularly haped, molded nuclei
- longitudinal nuclear grooves
- intranuclear cytoplasmic pseudoinclusion
- pale nuclei w/ powdery chromatin
- marginally placed micronucleoli, solitary or multiple
- psammoma bodies
- multinucleated giant cells
- variable colloid, stringy, ropy
- hurthle cell/squamous metaplsia
variants described features
follicular macrofollicular cystic oncocytic Warthin-like tall cell columnar cell
Follicular variant PTC
hypercellular/syncytial-like fragments w/ micorfollicles, clusters, isolated follicles,. sheets
- some colloid, typically thick
- nuclear changes subtle
- may not have: papillary, MNGC, INCI, psammoma bodies, cystic change
Macrofollicular variant PTC
-monolayered sheets of atypical epithelium and/or variably sized follicles
-nucelar features
-convincing nuclear changes must be present
abnudant thin colloid or fragmentso f thick colloid
Cystic variant PTC
- small groups with irregular borders, sheets, papillae, or follicles
- tumour cells look histiocytoid (hypervacuolated)
- macrophages, hemosideing
- variable thin or watery colloid
- convincing nuclear changes
- powdery chromatin usually less prominent (cellular degeneration and cell swirls/onion-skin appearance and cart wheel arrangement of follicular cells are more frequent
Oncocytic variant PTC
- oncocytic cells arranged in papillae, sheets or as isolated cells
- nuclear features of PTC
- lymphocytes are absent or few in number
Warthin-like variant PTC
- oncocytic and arranged in papillae and singles
- lymphoplasmacytic background
- lymphocytes in papillae and intimate assoc with follicular cells
- nuclear changes of PTC
Tall cell variant PTC
- elongated shape
- height to width ration of 3:1
- distinc cell border
- papillary fragments
- some lymphocytes
- nuclear features of PTC
- in contrast to conventional PTC: less powdery and more granular, psammoma bodies are few, INCI more frequent and multiple (soapbubble)
Columnar cell variant
- cellular and lack colloid
- papillae, clusters and flat sheets with small tubular structures
- nuclei elongated and stratified
- nuclear features of PTC
- -in contrast to conventional PTC: nuclear features can be focal(grooves, INCI), chromatin hyperchromatic rather than pale and powdery, colloid and cystic change
Hyalinising trabecular tumour
- cohesive neoplastic cells radially oriented around amyloid-like hyaline stromal material
- INCI and nuclear grooves numerous
- occasional psammoma bodies
- cytoplasmic paranuclear yellow bodies
Suspicious for PTC, Pattern A
Patchy nuclear changes
-moderately or highly cellul
-benign follicular cells (macrofollicle framents)
mix of cells with nuclear enlargement, nuclear pallor, nuclear grooves, nuclear membrane irregularity and or nuclear molding
-INCI rare or absent
Suspicious for PTC, Pattern B
Incomplete nucelar changes pattern
- sparsely, moderatly or highly cellular
- generlised mold to moderate nucelar enlargement iwth mild nucelar pallor
- nuclear grooves are evident but nucelar membrane irregularity and nuclear modling are minimal or absent
- INCI rare or absent
Suspicious for PTC, Pattern C
Sparsely cellular Pattern
-features of PTC but sample is very sparsely cellular
Suspicious for PTC, Pattern D
Cystic degeneration pattern
-hemosiderin-laden macrophages
-scattered groups and sheets of follicular cells have enlarge, pale nuclei and some have nuclear grooves but INCI are rare or absent
-occasional large, atypical, histocytoid cells with enlarged nuclei and abundant vacuolated cytoplasm
rare calcification that resemble psammoma bodies
Suspicious for medullary carcinoma
sparse to moderately cellular
- monomorphic population of noncohesive small or medium-sized cells with high NC ratio
- eccentric nuclei
- smudged chromatin with no cytoplasmic granules
- small fragments of amorphous material - colloid vs amyloid
Follicular neoplasm, Hurthle cell type
exclusively Hurthle cells
- abundant finely granular cytoplasm
- enlarged central or eccentrically located, round nucleus
- prominent nucleolus
- small cells with high NC ratio
- large cell with at least 2X variability in nuclear size
- Hurthle cells dispersed as isolated cells in syncytial-like arrangements
- little or no colloid or lymphocytes
- transgressing vessels
Follicular neoplasm
- moderately or markedly cellular
- alteration of follicular cell architecture, characterized by cell crowding, microfollicles and dispersed isolated cells
- follicular cells are normal-sized or enlarged and relatively uniform, with scant or moderate amount of cytoplasm
- nuclei are round and slightly hyperchromatic with inconspicuous nucleoli
- some nuclear typia may be seen with enlarged, variable sized nuclei and prominent nucleoli
- colloid scant or absent
FLUS/Atypi of undetermined significance
most common scenarios:
- population of microfollicles that does not fulfill criteria for FN
- predmoniance of H cells in sparsely cellular sample with scant colloid
- sample artifact hinders follicular cell atypia interpretation
- hypercellular specimen exculsively H cells, yet clinical setting suggests benign nodule (MNG, Hashimoto)
- focal features of PTC
- cyst-lining cells atypical with PTC features but otherwise benign
- minor population nuclear enlargement with promient nucleoli and: hx rads, thyroid altering drugs or reparte due to involution/cystic degen
- atypical lymphoid infiltrate
- NOS
Benign follicular nodule
- sparse to moderately cellular
- copious colloid thick or thin
- follicular cells are monolayered sheets and honeycombed
- some intact spheres
- rare microfollicles
- scant or moderate amounts of cytoplasm
- nuclei are dark, round to oval, size of rbc
- granular chromatin pattern
- anisonucleosis but not significant pleomorphism/atypia
- lipofuscin or hemosiderin
- H cells, macrophages can be present
- focal reparative hcanges
Hashimoto’s
hypercellular, unless fibrosed
- polymorphic lymphoid population with large reactive and small mature lymphocytes with occ plasma cells
- background or infiltrating lymphocytes into epithelial cell groups
- intact lymphoid follicles and lymphohistiocytic aggregates
- oncocytes arranged in sheets or as isolated cells
- abundant granular cytoplasm, large nuclei and prominent nucleoli
