Fine-needle aspiration cytology of papillary renal cell carcinoma: the association with concomitant secondary malignancies.

Papillary renal cell carcinoma is a rare type of renal malignancy. Cytogenetic findings characteristic for this tumor have been described as well as mutations of the proto-oncogene c-met. Secondary malignancies occurring together with papillary renal cell carcinomas are rare, and are often of genitourinary tract origin. We describe two cases of papillary renal cell carcinoma occurring in association with two other visceral malignancies, gastrointestinal stromal tumor and colon adenocarcinoma.Two cases of papillary renal cell carcinoma diagnosed by fine-needle aspiration (FNA), occurring in association with gastrointestinal malignancies were reviewed. Both aspirates showed cytologic features characteristic for papillary renal cell carcinoma, namely papillary structures, foamy histiocytes, intracytoplasmic hemosiderin, and nuclear grooves. Subsequent histology and immunohistochemical stains supported the cytologic diagnosis. The histologic diagnosis of gastrointestinal stromal tumor and colon adenocarcinoma were confirmed. Papillary renal cell carcinoma is a type of renal carcinoma that can be often accurately diagnosed by FNA. The occurrence of associated visceral malignancies has never been reported. The possible role of the protooncogene c-met in the development of these tumors was explored.