Sarcomatoid variant of urothelial carcinoma of renal pelvis with direct invasion of the pancreas and descending colon

Introduction Sarcomatoid variant of urothelial carcinoma infiltrates the perimeter and occurs occasionally. However, there are only few case reports. Case presentation A left renal tumor was incidentally detected in a 75‐year‐old woman and protruded outside the kidney, infiltrating the pancreatic tail and spleen. Tumor invasion was observed in the adjacent organs; therefore, the left kidney, pancreatic tail, spleen, and, descending colon were resected. Histopathological examination revealed a sarcomatoid variant of invasive urothelial carcinoma. She received two cycles of gemcitabine and carboplatin combination chemotherapy but succumbed to the disease after 5 months. Conclusion Sarcomatoid variant of urothelial carcinoma is rare, with aggressive malignancy. The diagnosis was difficult and required surgery. This is the first case of a sarcomatoid variant of urothelial carcinoma with direct invasion into the pancreas and descending colon.