History: 35 year old male with right sided scrotal pain.
The differential for this lesion is broad, however, in the absence of trauma or symptoms of infection, benign and malignant neoplasms are considered. The diagnosis in this case was Leydig cell tumor, which is a tumor of the testicular interstitial cells and is categorized with Sertoli cell tumors as a gonadal stromal cell tumor. Leydig cell tumors are typically benign when less than 3 cm, and malignant when greater than 5 cm. They comprise 3% of all testicular tumors, and 90% of the time are benign.