What is Leydig cell hyperplasia, and what are its cross-sectional imaging features?
Leydig cell hyperplasia is a rare benign condition that is characterized by the presence of hyperplastic Leydig cells within the testicle. Multiple 1- to 6-mm testicular nodules are characteristically visualized, often involving the testicles bilaterally.
On US, these nodules are usually hypoechoic and may demonstrate increased blood flow on Doppler US. On MRI, they have low T2-weighted signal intensity relative to testicular parenchyma and demonstrate mild enhancement.