Torsed appendix epididymis in an adult: misdiagnosis as tumor of tunica vaginalis on sonography.

We report the sonographic findings in a case of torsed appendix epididymis that occurred in an adult, which was misdiagnosed as a tunica vaginalis tumor such as cystic mesothelioma. Scrotal gray-scale sonography revealed an ovoid-shaped, heterogeneously hypoechoic mass with multiple tiny cystic foci and thick septa in the sac of the right tunica vaginalis, which abuts to the right epididymal head. Color Doppler sonography showed no blood flow within the mass. Pathological examination revealed torsion of the appendix epididymis.