Sarcomatous carcinoma with osteosarcomatoid differentiation of the bladder with simultaneous sigmoid colon adenocarcinoma.

Sarcomatoid carcinoma is a rare tumor of the urinary bladder and accounts for approximately 0.3% of all bladder malignancies. In these tumors, histogenesis and biological behaviour remains controversial. Herein, we report a case of sarcomatoid carcinoma with osteosarcomatoid differentiation of the urinary bladder with simulataneous sigmoid colon adenocarcinoma.