Osteoclast-like giant cell carcinoma of the urinary bladder.

Extraskeletal osteoclast-like giant cell (OGC) tumors are uncommon and have mainly been found in the breast and pancreas. OGC neoplasms of the urinary tract are extremely rare, and their histogenesis and biologic behavior remain controversial. Gross hematuria is the most common presenting symptom, as in transitional cell carcinoma. The prognosis is poor in patients with extraskeletal OGC tumors. Here, we present the case of a 62-year-old man who received transurethral bladder tumor resection due to painless gross hematuria. Pathology showed OGC carcinoma. Abdominal computed tomography showed tumor invasion over the right lateral wall of the bladder and distal third of the ureter. The patient received radical cystectomy and partial distal ureterectomy with transureteroureterostomy. No local tumor recurrence or distant metastasis was found at the 5-month follow-up.