An algorithmic approach to overcome diagnostic challenges in FNAC in large-cell poorly differentiated thyroid carcinomas

Microfollicular pattern may lead to these cases being misinterpreted as a differentiated follicular neoplasm on FNAC, and the dissociated large cells may mimic Hürthle cell neoplasm. Immunocytochemistry is not helpful in this scenario, although it does resolve the diagnostic dilemma when the differential diagnoses include medullary thyroid carcinoma and metastatic tumors. It is important to identify these tumors on FNAC as this facilitates proper management.