Primary extrarenal papillary type II renal cell carcinoma presenting as a pelvic mass: a case report and review of the literature

We report a case of a 57 years old woman with a solitary mass located in the pelvis diagnosed as an extrarenal papillary renal cell carcinoma, in the absence of a primary renal cancer. The diagnosis was based on cytomorphological features and further confirmed by immunochemistry findings following surgical excision. The hypothesis of a tumor developing in a supernumerary or ectopic kidney was excluded, since no normal renal tissue could be identified in the specimen and in the preoperative computed tomography and MRI images.