2. FNA of breast Slide session The 6th Arab-British School of Pathology
Nina S Shabb
AUBMC

3. Fibroepithelial lesions Cases 1-3
Fibroadenoma 3 components
Phyllodes tumor vs FA
Older women
Larger/cystic
Adequate sampling
Cellular stromal fragments
Cytologic atypia/mitosis (malignant)
Epithelial discohesion and atypia?
Adenocarcinoma arising in FA
PT misdiagnosed as adenocarcinoma
(proper preparation)

4. Fibroadenoma Most common cause of false positive dx
Cellular smear, may find single cells with atypia and discohesion
Do not spend too much time on high power looking for discohesive single cells.
Helpful feature: Numerous ME cells
Do not call malignant with numerous ME cells in background

5. Final dx Case 1: Case 2: Case 3: FNA dx: Cellular FA vs Benign PT.
Final dx: FA
Case 2:
Final dx: PT
Case 3:
PT/C4 (low grade carcinoma)

7. Ductal adenocarcinoma NOS Cases 4 and 5
Cytologic features?
Tumor cellularity
Discohesion
Single cells with features of malignancy
Grading
Nuclear grade 1-3

8. Final dx Case 4: Case 5 FNA dx: Adenoca NG 2/3
Final DX: Adenoca nos Grade 2/3
Case 5
FNA dx: Adenoca NG 1/3
Final DX: Adenoca nos Grade 1/3

10. Mucinous/colloid carcinoma Cases 6 and 7
Gross can mimic benign disease.
Mucin seen grossly while aspirating and smearing
Extracellular mucin on pap and DQ
Round balls of low grade tumor cells
If pure mucinous, has better prognosis but FNA can not determine that.
FNA: Suggestive of mucinous ca

11. Lobular carcinoma Case 8 and 9
What are the FNA features of classic lobular carcinoma?

12. Case 8
Classic lobular carcinoma

13. Case 9 Pleomorphic lobular ca Intraductal papilloma
How do we deal with papillary lesions on FNA?

15. Tubular ca Case 10
Angular, rigid, bent tubular clusters, sharp borders
Crowded nuclei
Minimal tumor discohesion
Dispersed single cells, minimal atypia
Absence/paucity of ME cells
Peripheral perpendicular cells

16. FNA of axillary LN Case 11
Metastatic adenocarcinoma c/w breast primary
False negative?
Other malignancy?

17. FNA of DCIS Case 12 DCIS Grade 3: DCIS cribriform DCIS grades 1 and 2:
Pleomorphic carcinoma cells, calcium, necrosis, macrophages
casting Calcification on mammogram
DCIS cribriform
Low grade carcinoma
punched out holes in cell clusters
DCIS grades 1 and 2:
No distinguishing features