This 55 y/o male was referred to ultrasound for evaluation of left scrotal tenderness and mass. Selected images from the ultrasound shown above demonstrate fine echogenicity in the hydrocele fluid on the left side. A high protein content and /or cholesterol crystals have been shown to be possible etiologies for the imaging findings. The lack of clinical symptoms will help to exclude an infectious etiology. In scrotal abscess (pyocele) in addition to the usual clinical symptoms, the fluid tends to have a "coarser" echogenicity as shown in the Case of the Week for March 20, 2000.