Primary solid neoplasms of the extratesticular tissues are rare. The reported prevalence rate of paratesticular neoplasms is between 3% and 16% of all patients referred for scrotal ultrasonography. A plasmacytoma is a discrete, solitary mass of malignant monoclonal plasma cells that can arise in any part of the body. In this report, we present a case of a paratesticular solid mass detected in an 80-year-old patient that proved to be primary extraosseous plasmacytoma on surgery, and discuss its sonographic features.