UNSUSPECTED METASTATIC RENAL-CELL CARCINOMA DIAGNOSED BY FINE-NEEDLE ASPIRATION BIOPSY - A REPORT OF 4 CASES WITH IMMUNOCYTOCHEMICAL CONTRIBUTIONS

Fine needle aspiration biopsy (FNAB) is currently considered a valid p rocedure in the diagnosis of various primary and metastatic neoplasms. It is also known that computed tomography (CT)-guided percutaneous FN AB of the kidney is very useful in diagnosing primary renal cell carci noma (RCC) and has a high accuracy rate. Nonetheless, its usage in the detection of unsuspected metastatic XCC has been described rarely. Be low we report four unusual cases of metastatic RCC discovered by FNAB. The patients presented with subcutaneous, pulmonary, adrenal and flan k masses with no previous history of ace, Immunocytochemical (ICC) sta ins, including cytokeratin, epithelial membrane antigen, vimentin and fat stain, were obtained on two cases and were very helpful in establi shing the diagnosis, We suggest that cytopathologists consider metasta tic XCC a possibility when evaluating patients with tumors of unknown origin and that FNAB can be useful in diagnosing unsuspected metastati c RCC, especially when assisted by ICC and fat stain.