Tumors of the testis. KVB. Important facts about testicular tumors. Uncommon, incidence: 5/100,000 men <1% of all malignancies in men Peak: 30-40 years, rare in prepubertal children & elderly >90% are of germ cell origin >90% are malignant
Embryonal carcinoma: Sheets of cells with large, hyperchromatic nuclei, prominent nucleoli and poorly-defined cell borders
Mature teratoma showing cysts lined by mucous epithelium (left) and keratinizing squamous epithelium (right).
Immature teratoma with primitive brain tissue (upper left corner) and well-differentiated glands (lower half).
Microscopically, the tumor is composed of two types of cells: Syncytiotrophoblasts, large multinucleate cells with abundant vacuolated cytoplasm containing hCG and Cytotrophoblasts, polygonal cells with distinct cell borders and single nuclei, which grow in clusters and are surrounded by the syncytiotrophoblasts
-Androgen excess: Premature puberty & macrogenitosomia
-Estrogen excess: Gynecomastia in adult males