PMC4900194_01
35-year-old man with epidermoid cyst of perineum. Ultrasonography revealed well-defined, oval hypoechogenic mass lesion with posterior acoustic enchancement (black arrow). Within the mass lesion, echogen foci (black arrowhead) without posterior shadowing and anechoic cystic spaces (white arrowhead) appeared.
gr1.jpg
PMC4900194_01_gr1.jpg
fig1
Within the lesion were discrete echogenic foci without posterior acoustic shadowing and anechoic cystic spaces (Fig. 1).
35-year-old man with epidermoid cyst of perineum. Mass-oriented MRI includes (A) coronal T1WI, (B) coronal T2 WI, (C) diffusion-weighted image (b:1000 s/mm2), (D) ADC mapping with calculated ADC value of 1.01, (E) axial fat-suppressed T2WI, (F) axial precontrast T1WI, and (G) axial gadolinium-enchanced T1 WI views. The lesion is indicated with a white arrowhead (A, C, D) and a white arrow (B, E, F, G).
gr2.jpg
PMC4900194_01_gr2.jpg
fig2
T1-weighted images (Fig. 2A). T2-weighted images (Fig. 2B) and fat-suppressed, T2-weighted images (Fig. 2E) demonstrated a hyperintense mass lesion. After gadolinium injection, peripheral thin enhancement was noted (Fig. 2G). DW MRI revealed significant diffusion restriction (Figs. 2C and 2D) with a calculated ADC value of 1.01.
35-year-old man with epidermoid cyst of perineum. X10 preparation stained with hemotoxylin-eosin shows a cyst wall lined with stratified squamous epithelium with distinct granular layer (black arrowhead).
gr3.jpg
PMC4900194_01_gr3.jpg
fig3
After histopathologic evaluation, the mass was confirmed as an epidermoid cyst (Fig. 3).