Biphasic tumors of the seminal vesicle are rare. We report a further case in a 61-year-old man of a seminal vesicle epithelial-stromal tumor with focally atypical epithelial and stromal cells, the latter displaying a smooth muscle immunophenotype. In addition, this was associated with 2 synchronous malignant neoplasms, chromophobe renal cell carcinoma and small lymphocytic lymphoma, both of which were detected incidentally after clinical presentation because of the seminal vesicle mass.