Bethesda system for reporting thyroid malignancy

1. BETHESDA SYSTEM
FOR REPORTING
THYROID
CYTOPATHOLOGY
Guide : Dr Sharada Rane
PG : Dr Gourav
Agrawal

2. Introduction
☛Bethesda System for Reporting
Thyroid Cytopathology (BSRTC)
recommends that each thyroid FNA
report should begin with a general
diagnostic category.
☛The motive behind is to bring clarity
of communication amongst
pathologists and amongst
pathologist and clinicians.

3. 1. Nondiagnostic or Unsatisfactory
2. Benign
3. Atypia of Undetermined Significance or
Follicular Lesion of Undetermined
Significance
4. Follicular Neoplasm or Suspicious for a
Follicular Neoplasm
5. Suspicious for Malignancy
6. Malignant

4. Category I
Nondiagnostic or
Unsatisfactory

5. ☛Fewer than six groups of well-
preserved, well-stained follicular cell
groups with ten cells each
☛Poorly prepared, poorly stained, or
obscured follicular cells
☛Cyst fluid, with or without histiocytes,
and fewer than six groups of ten
benign follicular cells

6. Nondiagnostic (cyst fluid only). Abundant hemosiderin-laden
macrophages

7. Nondiagnostic. The smear shows abundant red cells, with rare
lymphocytes

8. Nondiagnostic. Extensive air-drying artifact in this alcohol-fixed
smear

9. Exceptions
1. Solid nodules with cytologic atypia
• Any significant atypia has to be reported
• Minimum number of cells not required
2. Solid nodules with inflammation
• Thyroiditis may show only infammatory
cells
• Minimum number of cells not required
3. Colloid nodules
• Minimum number of cells is not
required if easily-identifiable colloid

10. Category II
Benign

11. Benign Follicular Nodules (BFNs)
● nodules in nodular goiter (NG)
● hyperplastic (adenomatoid) nodules
● colloid nodules
● nodules in Graves’ disease
● subset of follicular adenomas (those of
macrofollicular type)
Thyroiditis
● Lymphocytic, Acute, Sub-acute, Riedel’s

12. Benign Follicular Nodule
☛ Colloid
● dark blue-violet-magenta with
Romanowsky
● green to orange-pink with
Papanicolaou
● Thin colloid - “thin membrane/cellophane”
or “crazy pavement” or “chicken wire”
or mosaic appearance
● Dense colloid - hyaline quality and shows
cracks
☛ Follicular cells - arranged predominantly in
monolayered sheets and are evenly spaced

13. BFN : Watery colloid has a light green-pink color and shows a
“thin membrane/cellophane coating” appearance

14. Benign follicular nodule: Thick colloid demonstrates
a “stained glass cracking” appearance

15. BFN : Predominantly monolayered sheets of follicular cells are
admixed with occasional pigment-laden macrophages

16. Grave’s Disease
☛ Lymphocytes may be seen in the
background.
☛ Follicular cells are arranged in flat sheets
and loosely cohesive groups, with
abundant delicate, foamy cytoplasm.
☛ Nuclei are often enlarged, vesicular, and
show prominent nucleoli.
☛ Few microfollicles may be observed.
☛ Distinctive flame cells may be prominent,
and are represented by marginal
cytoplasmic vacuoles with red to pink

17. Large monolayered sheets of cells have abundant cytoplasm. Flame cells
are distinctive, with marginal cytoplasmic vacuoles with red to pink

18. Hashimoto’s Thyroiditis
☛ Usually hypercellular, but does not require
a minimum number of follicular/Hürthle
cells for adequacy.
☛ The lymphoid population is polymorphic,
including small mature lymphocytes,
larger reactive lymphoid cells, and
occasional plasma cells.
☛ Hürthle cells (oncocytes), when present,
are arranged in sheets or as isolated cells.
They have abundant granular cytoplasm,
large nuclei, and prominent nucleoli

19. Lymphocytic (Hashimoto’s) thyroiditis. There is a mixed population
of Hürthle cells and polymorphic lymphocytes

20. Granulomatous/de Quervain’s
thyroiditis
☛ Clusters of epithelioid histiocytes, i.e.,
granulomas, are present along with many
multinucleated giant cells.
☛ Early stage - many neutrophils and
eosinophils, similar to acute thyroiditis.
☛ Late stages - smears are hypocellular. They
show giant cells surrounding and
engulfing colloid, epithelioid cells,
lymphocytes, macrophages, and scant
degenerated follicular cells

21. Granulomatous (de Quervains) thyroiditis. Epithelioid granulomas, mixed
inflammatory cells, and benign follicular cells are present. Macrophage with

22. Acute thyroiditis
☛ Numerous neutrophils are associated with
necrosis, fibrin, macrophages and blood.
☛ There are scant reactive follicular cells and
limited to absent colloid.
☛ Bacterial or fungal organisms are
occasionally seen in the background
especially in immunocompromised
patients.

23. Acute thyroiditis. There are numerous neutrophils, macrophages,
and inflammatory debris

24. Riedel’s Thyroiditis
☛The thyroid gland feels stony hard on
palpation.
☛The preparations are often acellular.
☛Collagen strands and bland spindle cells
may be present.
☛There are rare chronic inflammatory
cells.
☛Colloid and follicular cells are usually
absent

25. Riedel´s thyroiditis. The hypocellular smear contains
scattered bland spindle cells and rare chronic inflammatory cells

26. Category III
Atypia of Undetermined
Significance/Follicular
Lesion of Undetermined
Significance

27. ☛ specimens that contain cells
(follicular, lymphoid, or other) with
architectural and/or nuclear atypia
that is not sufficient to be classified
as suspicious for a follicular
neoplasm, suspicious for malignancy
or malignant
☛ On the other hand, the atypia is
more marked than can be ascribed
confidently to benign changes

28. Examples :
☛ Predominance of Hürthle cells in a sparsely
cellular aspirate with scant colloid
☛Focal features suggestive of papillary
carcinoma in an otherwise predominantly
benign-appearing sample
☛Cyst-lining cells which may appear atypical
due to nuclear features in an otherwise
predominantly benign-appearing sample.
☛Atypical lymphoid infiltrate but the degree
of atypia is insufficient for the general
category “suspicious for malignancy.”

29. AUS. Sparsely cellular specimen with a predominance of
microfollicles. Inset : high magnification of a microfollicle

30. AUS (a) heterogeneous infiltrate of lymphoid cells, including occasional
atypical

31. Category IV
Follicular Neoplasm/Suspicious
for a Follicular Neoplasm
Follicular Neoplasm, Hürthle Cell
Type/Suspicious for a Follicular
Neoplasm, Hürthle Cell Type

32. ☛ Significant alteration in the 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 amounts of cytoplasm.
☛ Nuclei are round and slightly
hyperchromatic, with inconspicuous nucleoli
☛ Colloid is scant or absent.
Follicular Neoplasm/Suspicious
for a Follicular Neoplasm

33. Highly cellular aspirate composed of uniform follicular cells arranged
in crowded clusters and microfollicles

34. Follicular neoplasm/Suspicious for a follicular neoplasm.
Microfollicles may contain small amounts of colloid

35. Follicular Neoplasm, Hürthle Cell
Type/Suspicious for a Follicular
Neoplasm, Hürthle Cell Type
☛ Exclusively (or almost exclusively)
Hurthle cells
☛ abundant finely granular cytoplasm
☛ enlarged, central or eccentrically located,
round nucleus with prominent nucleolus

36. The aspirate is very cellular and consists of Hürthle cells of variable
size arranged as isolated cells and in crowded groups; colloid is absent

37. The aspirate consists of a population of loosely cohesive Hürthle cells.
The cells are highly variable in size and amount of cytoplasm

38. Category V
Suspicious for
Malignancy

39. Sub-categories
☛ Suspicious for Papillary Carcinoma
• Pattern A - Patchy nuclear changes
pattern
• Pattern B - Incomplete nuclear changes
pattern
• Pattern C - Sparsely cellular specimen
pattern
• Pattern D - Cystic Degeneration pattern
☛ Suspicious for Medullary Carcinoma
☛ Suspicious for Lymphoma
☛ Suspicious for malignancy, not

40. The aspirate consists of a population of loosely cohesive Hürthle cells.
The cells are highly variable in size and amount of cytoplasm

41. The aspirate consists of a population of loosely cohesive Hürthle cells.
The cells are highly variable in size and amount of cytoplasm

42. Category V
Malignant

43. Sub-categories
☛ Papillary Thyroid Carcinoma
☛ Medullary Thyroid Carcinoma
☛ Poorly differentiated Thyroid
Carcinoma
☛ Undifferentiated (Anaplastic)
Carcinoma and Squamous Cell
Carcinoma of the Thyroid
☛ Metastatic tumors and lymphoma

44. Papillary Carcinoma
Thyroid
☛ Follicular cells are arranged in papillae
and/or syncytial-like monolayers.
☛ Swirling sheets (“onion-skin”) sometimes
seen.
☛ Characteristic nuclear features:
• Enlarged nuclei
• Oval or irregularly shaped, with marked
overlapping.
• Longitudinal nuclear grooves
• Intranuclear cytoplasmic pseudoinclusions
(INCI)
• Pale nuclei with powdery chromatin (“Orphan

45. Papillary Carcinoma Thyroid
☛ Psammoma bodies are sometimes
present.
☛ Multinucleated giant cells are
common.
☛ The amount of colloid is variable and
may be stringy, ropy, or “bubble-gum”
like.
☛ Hürthle cell (oncocytic) metaplasia is
sometimes seen.

46. Papillary Thyroid Carcinoma. There is a mix of flat sheets and
rounded, papillary-like fragments without fibrovascular cores

47. Papillary thyroid carcinoma. There is marked crowding of the
neoplastic

48. PTC. Large sheet of tumor cells with crowded, “Orphan Annie eye”
nuclei.

49. Medullary Thyroid Carcinoma
☛ Moderate to marked cellularity.
☛ Numerous isolated cells alternate with
syncytial-like clusters in variable proportions
from case to case.
☛ Cells are plasmacytoid, polygonal, round,
and/or spindle-shaped, with moderate to
abundant cytoplasm, eccentric nucleus and
smudged chromatin
☛ The neoplastic cells usually show only mild
to moderate pleomorphism.
☛ Fragments of amorphous material - colloid
versus amyloid.

50. Predominantly dispersed, uniform plasmacytoid or polygonal cells
have granular (“salt and pepper”) chromatin and small but distinct

51. Medullary thyroid carcinoma. Amyloid is abundant and readily
appreciated in some cases

52. Poorly Differentiated Thyroid
Carcinoma
☛ Cellular preparations display an insular,
solid, or trabecular cytoarchitecture
☛ There is a uniform population of
follicular cells with scant cytoplasm
(sometimes plasmacytoid)
☛ The malignant cells have a high
nuclear/cytoplasmic (N/C) ratio with
variable nuclear atypia
☛ Apoptosis and mitotic activity are
present

53. Poorly differentiated thyroid carcinoma. Aspirates show marked
pleomorphism which are mitotically active.

54. Poorly differentiated thyroid carcinoma.
Aspirates exhibit marked nuclear atypia with impressive

55. Undifferentiated (Anaplastic)
Carcinoma and Squamous Cell
Carcinoma of the Thyroid
Undifferentiated (Anaplastic)
Carcinoma
☛ Neoplastic cells are arranged as isolated
cells and/or in variably sized groups.
☛ Neoplastic cells are epithelioid (round to
polygonal) and/or spindle-shaped and
range in size from small to giant-sized.
“Plasmacytoid” and “rhabdoid” cell shapes

56. ☛ Nuclei show enlargement, irregularity,
pleomorphism, clumping of chromatin
with parachromatin clearing, prominent
irregular nucleoli, intranuclear inclusions,
eccentric nuclear placement, and
multinucleation.
☛ Necrosis, extensive inflammation
(predominantly neutrophils, “abscess-like”)
and/or fibrous connective tissue may be
present.
☛ Osteoclast-like giant cells (non-neoplastic)
are conspicuous in some cases.
☛ Neutrophilic infiltration of tumor cell
cytoplasm can be seen.

57. Cells are epithelioid (polygonal) in appearance. Variation in cell and
nuclear size is evident.

58. Squamous Cell Carcinoma
☛ Cytologic samples are composed
almost exclusively of large,
pleomorphic keratinized cells.
☛ Necrosis may be present.

59. Large pleomorphic cells with dense cytoplasm. There is abundant
necrosis, and nuclei show degenerative changes

60. Sample Reports – Nondiagnostic or
Unsatisfactory

61. Sample Reports – Benign

62. Sample Reports – Atypia of Undetermined
Significance

63. Sample Reports – Follicular Neoplasm/
Suspicious for a Follicular
Neoplasm

64. Sample Reports – Suspicious for a
Malignancy

65. Sample Reports – Malignant

66. 1. Nondiagnostic or Unsatisfactory
2. Benign
3. Atypia of Undetermined Significance or
Follicular Lesion of Undetermined Significance
4. Follicular Neoplasm or Suspicious for a
Follicular Neoplasm
5. Suspicious for Malignancy
6. Malignant
THANK
U
BSRTC