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

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

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

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

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)

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

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)

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

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

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

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

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

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

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).

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