Primary seminal vesicle carcinoma detected at transurethral resection of prostate

We present a case of primary seminal vesicle carcinoma detected at transurethral resection. The clinical presentation, radiologic findings, and pathologic features of these tumors are reviewed. Grossly, seminal vesicle carcinoma is poorly circumscribed and solid or solid/cystic and may be misinterpreted as an abscess or hemorrhage on radiologic examination. Although a definitive diagnosis often cannot be given until after complete resection, we describe the findings indicative of seminal vesicle origin, including papillary histologic architecture, sometimes with mucinous differentiation, and a characteristic immunophenotype positive for CA-125 and cytokeratin 7, but negative for prostate-specific antigen and cytokeratin 20.