Teratocarcinoma-leydig cell tumors comprise between 1% and 3% of all testicular tumors and about 3% are bilateral. most occur in adults with a palpable testicular mass. they may produce endocrine changes because of increased production of androgens and/or estrogens. gynecomastia is the most common symptom. in children, it manifests as sexual precocity. grossly, they are circumscribed nodules less than 5cm in diameter with a cut surface showing a distinct golden brown homogenous appearance. microscopically, the tumor cells are large to polygonal with round to oval nucleus and deeply acidophilic abundantly granular cytoplasm. the cell boundaries are often indistinct. the cytoplasm shows lipochromic pigment and rod shaped crystalloids of reinke. most are benign, but 10% are invasive and metastasize.sertoli cell tumors occur in all age groups and present with gynecomastia in 1/3 of all cases. grossly, the tumors are well-circumscribed, white or yellow, and firm, with focal cystic areas. microscopically, the diagnostic feature is the presence of tubular formations lined by elongated cells having the appearance of sertoli cells. in other areas, the tumor is solid and can be confused with seminomas. most are benign with 10% pursuing a malignant course.seminomas make up to 30%-40% of testicular tumors and are the most common type of germ cell tumors. the seminomas are divided into 2 major categories: classical and spermatocytic seminomas. the classic seminomas are of moderate size, solid, homogenous, light yellow, and may contain sharply circumscribed zones of necrosis. areas of cystic change or hemorrhage are usually not seen. microscopically, the individual tumor cells are uniform, large, round to polyhedral cells. there is a distinct cell membrane with abundantly clear cytoplasm and large central nucleus with 1 or 2 prominent nucleoli. the tumor cells are characteristically arranged in nests outlined by fibrous bands and these bands are infiltrated by lymphocytes and plasma cells.teratocarcinoma is composed of a mixture of adult teratoma and embryonal carcinoma. its gross appearance depends on the relative amount of these 2 components: multicystic in areas of adult teratoma, and solid with hemorrhagic and necrotic foci in the areas of embryonal carcinoma. the appearance of teratomatous foci ranges from mature to immature.mature teratomas constitute 5% to 10% of all the testicular tumors. it is predominantly cystic and multiloculated. foci of cartilage are usually evident, but the presence of bone is infrequent. microscopically, all types of tissues may be seen, with the most common being nerve, cartilage, and various types of epithelium. to diagnose adult teratoma, all the tissues that are present should be well differentiated or mature.immature teratomas show some areas of tissue immaturity, which may be in the stroma, the epithelial, or in the neural component. this may range from a slight hypercellularity of the stroma around the glandular component to large foci of primitive glands or neuroepithelium.
