Image Description
Sarcomatoid urothelial carcinomas may show heterologus differentiation consisting of rhabdomyosarcoma, osteosarcoma, chondrosarcoma (shown here), and other elements. In this image, the surface shows urothelial carcinoma-in-situ and the lamina propria shows low-grade chondrosarcoma. The differential diagnosis includes the isolated cases of urothelial carcinoma with benign metaplastic bone or cartilage in the stroma.