title: Testicular epidermoid cysts: sonographic features with histopathologic correlation.
abstract: Testicular epidermoid cysts are rare, accounting for 1% of all testicular tumors. We present the sonographic appearances of epidermoid cysts in 3 cases, together with the histopathologic correlation. In case 1, sonography showed an intratesticular hypoechoic mass with a well-defined echogenic rim; the mass measured 1.8 x 1.5 x 1.5 cm, and there was no evidence of calcification. In case 2, sonography showed a well-circumscribed mass measuring 1.3 x 1.3 x 1.0 cm, with alternating hypoechoic and hyperechoic rings (onion-ring appearance) and no calcifications. In case 3, sonography showed a 2.4- x 2.3- x 2.3-cm, well-circumscribed, oval mass with a heterogeneous echotexture and an outer hypoechoic halo. The mass contained plaque-like regions of increased echogenicity, with peripheral acoustic shadowing from refraction artifact. Hypoechoic clefts were visualized posterior to the plaque-like areas. The triad of findings-sonographic appearance of an onion ring, avascularity on Doppler sonography, and negative results of tumor marker studies-is highly suggestive of an epidermoid cyst.
authors.affiliation: Department of Radiology, Mercy Medical Center, North Eastern Ohio Universities College of Medicine, 1320 Mercy Drive NW, Canton, Ohio 44708, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Dogra
authors.forename: R H
authors.initials: RH
authors.lastname: Gottlieb
authors.forename: D J
authors.initials: DJ
authors.lastname: Rubens
authors.forename: M
authors.initials: M
authors.lastname: Oka
authors.forename: A P
authors.initials: AP
authors.lastname: Di Sant Agnese
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor; D003937:Diagnosis, Differential; D004814:Epidermal Cyst / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D013733:Testicular Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D013736:Testicular Neoplasms / Q000175:diagnosis; D018608:Ultrasonography, Doppler
chemical_list: D014408:Biomarkers, Tumor