Genitourinary Disorders Chapter 233. The origin and nature of scrotal masses must be determined accurately because most testicular masses are malignant and extratesticular masses benign. The incidence is 2.5 to 20 times higher in patients with cryptorchidism, even if the undescended testis has been brought down surgically. The normally descended testis is also at risk for tumor. The cause of testicular tumors is unknown.
Histologic combinations are common, eg, teratocarcinoma contains teratoma plus embryonal carcinoma.
Functional interstitial cell carcinomas of the testis are rare. Tumors arising in the epididymis, testicular appendages, and spermatic cord usually are benign fibromas, fibroadenomas, adenomatoid tumors, and lipomas. Sarcomas, most commonly rhabdomyosarcoma, occur occasionally, mostly in children. The usual presenting sign is a scrotal mass, sometimes associated with pain. Many patients discover the mass in association with minor trauma.