[Osteoclast-Like giant cell bladder carcinoma: Case report].

Background: Osteoclast-like giant cell bladder carcinomas are an extremely unusual and aggressive histological subtype of urothelial carcinomas. Only 30 cases are reported in the international literature.

Clinical Case: A 79-year-old male patient attended our Urology department for a six-month history of macroscopic hematuria. As part of its diagnostic protocol, a CT scan of the abdomen and pelvis with elimination phase was performed, finding a 12-mm filling defect at the level of the posterior wall of the bladder; subsequently, a cystoscopy was performed confirming the presence of a 1.5 cm bladder tumor, which was completely resected. Pathology analysis with hematoxylin and eosin staining revealed a composition of mononuclear cells and osteoclast-like giant cells; immunohistochemistry was positive for epithelial markers CK AE-1 / AE-3, EMA, P53 and CD68.

Conclusions: These tumors are extremely unusual and aggressive. The only diagnostic method is through immunohistochemistry where the presence of epithelial markers for urothelium in neoplastic cells is confirmed. Radical surgical treatment is recommended and to date there is no proven effective adjuvant treatment. Its median overall survival is 15 months.