1. FNAC for Diagnosis - the very basic for ALL –
16Jun2018
Dr Lam Wing Yin
Consultant Pathologist
Tuen Mun Hospital

2. How to Evaluate your FNA smear
ensure Everything examined
always starts with direct eyeballing
4X POWER examination is crucial
Do not forget the smear/glass edges

3. 5 main attributes to assess
Cellularity
The cellular composition in the aspirate
The architecture (cell arrangement) of the aspirated cells
Cytomorphology of the lesion cells
The slide background

4. Cellularity Benign tumor lesions tend to be hypocellular
Malignant tumor FNA showed high cellularity
Exceptions always

5. Cellular composition in the aspirate
answer the following Qns:
Is there only 1 cell type in the smear
1 cell type in general = from a Neoplasm
N.B. 1 cell type can be uniform or polymorphic
Are there >1 cell types in the smear;
are they from same tissue, or from different sources?
Some tumors showed >1 cell type (e.g. Pleom Adenoma, Synovial SA, MMMT)
Is there a mixture of benign & Malignant cells ( prostate CA, 2*CA in LN0)

6. Cellular Patterns and Architecture
i.e. = How cells are arranged in the aspirate/smears
Degree of cohesiveness is crucial
Often, this is the clue to Benignity vs Malignancy

7. Cell pattern/Architure (2)
Dispersive cell pattern
Glandular, with lumina
Acinar / Rosettes
Fragments with demarcated borders
Papillary
Cell balls
Cell balls with fenestrations (cribriform)
Trabecular (thick or thin)
Fascicular
Mixed (squamous and glands; epithelial and lymphoid; spindle and epithelioid etc)

8. CytoMorphology
Nuclear alterations basically indicates benignity vs malignancy (exceptions+)
Cytoplasmic textures and staining indicate the function and type of the cells

9. CytoMorphology (1) Exceptional scenarios
Nuclear alterations often indicates benignity vs malignancy (exceptions+)
Nuclear enlargement ( & N/C ratio)
Nuclear size and shape variation
Nuclear membrane irregularity
Nuclear chromasia
Nuclear chromatin irregularity
Macronucleoli
Abnormal mitosis
Exceptional scenarios
Degenerative cells (schwannoma), RT/CT effect, endocrine tumors, pleomorphic mesenchymal tumor

10. CytoMorphology (2)
Cytoplasmic textures and staining indicate the function and type of the cells
Squamous cells
Malignant columnar cells
Vacuolated cells (nuclear compression?)
Polygonal cells + Granular cells
Small round cells
Plasmacytoid cells
Spindle cells
bizarre cells
Nuclear grooving; macronucleoli
Cytoplasmic granules, pigments, inclusions, lipid & glycoen

11. Smear Background Diathesis vs clean Mucin
Stromal substances (fibromyxoid fragments, fibrillary material, colloid)
psammomas

12. 5 main attributes to assess
Cellularity
The cellular composition in the aspirate
The architecture (cell arrangement) of the aspirated cells
Cytomorphology of the lesion cells
The slide background

13. Reporting (1) Remember your report may be Definitive and Final for Mx
5 Classes-system is simple and often practical
C1: inadequate, non diagnostic, unsatisfactory
C2: benign
C3: atypical, Indeterminate, IDK
C4: suspicious
C5: diagnostic malignant
Additional information needed for management
Confirming a suspected DIAGNOSIS, or excluding a Dx
Recommending Treatment (if deem necessary), or
indicate further Investigations/additional information

14. Reporting (2)
If a Histologic confirmation is need, say so in the report
If no definitive diagnosis, suggest your differential diagnosis according to their likelihood
For a ‘NEGATIVE’, best to clearly state it is to mean
The lesion is a benign lesion, or
There are only normal cells intrinsic to the site aspirated.
The report should be formulated with due CLINICOPATHOLOGIC CORRELATION, understanding of the clinical implication & attention to Diagnostic Pitfalls (F-ve/F+ve).

15. END
THANK YOU