The endocrinology of testicular tumors

The endocrine manifestations of testicular tumors can be produced by one of three mechanisms: direct synthesis of androgens or estrogens by the tumors; synthesis of gonadotropins that stimulate secondary secretion of androgens or estrogens; alteration of the peripheral metabolism of androgens. In this manuscript the authors have discussed these mechanisms in relationship to steroid secreting tumors and gonadotropin secreting tumors. In postpubertal males, the most common manifestation of these tumors is the production of gynecomastia. Because the breast is a target organ for the action of both androgens and estrogens, gynecomastia occurs when there is an alteration in the normal androgen/estrogen ratio. Consequently, gynecomastia may be produced by either deficient androgen production or excessive estrogen secretion. The endocrinology of testicular tumors is a fascinating subject and recent development of sensitive specific radioimmunoassays for the measurement of tumor markers has opened a new area of investigation into the biology of these neoplasms.