mooth muscle hyperplasia of the epididymis is a rare condition and is seen as non-neoplastic proliferation of smooth muscle, which forms smooth muscle fascicles arranged in a periductal, perivascular, interstitial, or mixed pattern.
1Although several cases of smooth muscle hyperplasia of the epididymis have been described in the pathologic literature, 1-3 to the best of our knowledge, sonographic findings have not been described. We report the sonographic findings of a case of smooth muscle hyperplasia of the epididymis that presented as a solid mass.
Case ReportA 47-year-old man was admitted with a 4-week history of a left scrotal mass. There was no history of genitourinary problems. A physical examination revealed the presence of a hard nontender mass in the tail of the left epididymis. The mass measured approximately 1 cm in diameter. The right testis and epididymis were normal. Scrotal sonography was performed with a 5-to 12-MHz linear array transducer attached to an iU22 scanner (Philips Healthcare, Bothell, WA). Gray scale sonography showed the presence of a well-defined solid mass in the left epididymal tail. The mass showed a heterogeneous echo texture with echogenicity similar to that of the adjacent testis and had a thin hypoechoic rim ( Figure 1A). On color Doppler sonography, no blood flow within the mass was depicted. An increase in perilesional blood flow was seen ( Figure 1B).The patient underwent surgical excision of the mass and a left epididymectomy. A gross pathologic examination showed a firm yellowish-whitish mass measuring 1 × 0.8 × 0.6 cm in the epididymal tail ( Figure 1C). A microscopic examination showed a proliferation of smooth muscle encasing dilated epididymal ducts (Figure 1, D and E). The pathologic diagnosis was smooth muscle hyperplasia of the epididymis.