Testicular Yolk Sac Tumor

**Semantic type:** Neoplastic Process

**Definition:** A non-seminomatous malignant germ cell tumor arising from the testis. It affects infants, young children, and postpubertal males. It is the most frequently seen testicular neoplasm during childhood. The vast majority of patients present with an asymptomatic scrotal mass. The tumor mimics the yolk sac of the embryo and produces alpha-fetoprotein (AFP). It metastasizes to distant anatomic sites. Prognostic factors relate to the clinical stage and the degree of AFP elevation.

**Synonyms:** - Endodermal Sinus Neoplasm of Testis - Endodermal Sinus Neoplasm of the Testis - Endodermal Sinus Tumor of Testis - Endodermal Sinus Tumor of the Testis - Testicular Endodermal Sinus Neoplasm - Testicular Endodermal Sinus Tumor - Testicular Yolk Sac Neoplasm - Yolk Sac Neoplasm of Testis - Yolk Sac Neoplasm of the Testis - Yolk Sac Tumor of Testis - Yolk Sac Tumor of the Testis