Diagnosis of a small Leydig cell tumor by dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging.

Leydig cell tumors are usually small and resemble normal ovarian stroma, so they are often difficult to localize. Here, we present a rare case in 39-year-old woman which dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging findings showed some differences between a Leydig cell tumor and normal ovarian stroma. Combining these 2 MRI techniques may be useful for diagnosing a Leydig cell tumor.