Clear cell variant of urothelial carcinoma in urinary bladder; a clinicopathological and immunohistochemical study--a case report.

The clear cell variant urothelial carcinoma of urinary bladder is very rare and unusual neoplasm defined histologically by clear cell pattern and glycogen-rich cytoplasm. Our case of clear cell carcinoma was diagnosed with immunohistochemistry stain. A 72-year-old man, presented with painless macroscopic hematuria in November 2007. Evaluation revealed papillary tumor in urinary bladder. A transurethral resection of the bladder tumor (TUR-Bt) was performed. Histopatologic evaluation showed superficial transitional cell carcinoma and carcinoma in situ. On three month follow-up, a solitary pedunculated tumor was detected again in the left wall of the urinary bladder. A repeated transurethral resection of the bladder tumor (reTUR-Bt) was performed in February 2008. The pathological diagnosis was difficult due to diffuse clear cell appearance. Immunohistochemistry stain showed urothelial carcinoma and finally it was diagnosed as clear cell variant. Urothelial carcinoma has many variants that show a variety of appearances and characteristics. These should be well known for evaluation and optimal treatment.