Clear cell adenocarcinoma of bladder expressing prostate-specific antigen, alpha-methylacyl-CoA racemase and CD10

Abstract

Backgrounds: Clear cell adenocarcinoma (CCA) of urinary bladder (UB) is rare.

Aims: To report a case of CCA of UB immunohistochemically expressing prostate-specific antigen (PSA), alpha-methylacyl-CoA racemase (AMACR) and CD10; thus this case was difficult to differentiate from metastasis from prostatic adenocarcinoma or renal cell carcinoma (RCC).

Case: An 84-year-old man presented with dysuria and hematuria, and cystoscopy revealed a bladder tumor. The biopsy showed proliferation and invasion (more than pT2) of high-grade carcinoma cells focally forming glandular structures. Lymphovascular permeations were recognized. Focally, usual urothelial carcinoma (UC) was seen and there were gradual direct transitions between the clear cell carcinoma and UC. Immunohistochemically, the carcinoma cells were positive for PSA, AMACR, CD10, p53, Ki67 (labeling = 10%), uroplakin II, thrombomodulin, and cytokeratin (CK) 20, but negative for Hepatocyte-paraffin1 (HepPar1), CK7, PAX8, and TTF-1.

Conclusions: A rare case of CCA of UB with immunoexpressions of PSA, AMACR and CD10 is reported. The aberrant expressions of these three antigens are only speculative. The gradual transitions between UC and CCA and the presence of urothelial antigens in this tumor suggest that the tumor might have originated from UC.