Abstract
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.