13 - Neoplasms of the Testis

Abstract

Although weighing only about 19 grams, the testis is responsible for a complex array of neoplasms. The rapidly proliferating spermatogenic cells give rise to the majority of testicular tumors, 95% of which are of germ cell derivation. Most are malignant and usually occur in young men, but they can be cured by current therapies; therefore accurate diagnosis is essential. The supporting cells and interstitial cells of the testis are responsible for the less common sex cord–stromal tumors that compose a disproportionate number of diagnostic problems. Some of these are associated with clinical syndromes that may be suspected based on the testicular pathology. A number of tumors of soft tissue origin may be identified in the paratestis, and secondary tumors are relatively frequent in both the testis and paratestis. The spectrum of lesions and the capacity of many tumors to mimic others make testicular neoplasia a continuing challenge to surgical pathologists, and this topic has been the subject of several recent reviews.