Primary seminal vesicle epithelioid smooth muscle neoplasm of uncertain biologic potential.

We present the case of a 73-year-old male patient who presented with obstructive urinary symptoms, pelvic pressure, and hematuria. CT imaging revealed a heterogenous prostate enlargement, and MRI demonstrated the mass to be arising from the seminal vesicle. Prostate biopsies showed benign tissue. Surgical excision was completed and pathology revealed it to be an epithelioid smooth muscle neoplasm of uncertain biologic potential. This is only the second known case of such a seminal vesicle tumour. As soft tissue sarcomas of the seminal vesicle emerge in the literature, we may develop a better understanding of their biologic behaviour and prognostic potential.