Sarcomatoid Renal Cell Carcinoma Diagnosed by Percutaneous Needle Biopsy

A 56-year-old man presented with discomfort in the abdomen and backache. He lost his body weight by 10 Kg in 6 months.A large retroperitoneal mass was found in addition to the right renal mass.It seemed necessary to exclude additional tumor in theretroperitoneum.Abdominal CT with and without contrast enhancement showed Tumors in the right kidney and giant tumors in the retroperitoneum. Percutaneous core needle biopsy of the retroperitoneal tumor and renal tumor was carried out under CT control.Pathological study revealedsarcomatoid renal cell carcinoma in the retroperitoneal mass, but mostly fibrous tissue in the renal mass.Final diagnosis was sarcomatoid renal cell carcinoma with retroperitoneal extension. This type of renal cell carcinoma is noted to have very poor prognosis in the literature. Our case was also poor in prognosis, and the patient expired three months after the diagnosis was established.