GNRH1 and columnar cell hyperplasia of the breast: Testicular ultrasonography can be used to determine testicular volume, omitting the contribution of the epididymis and overlying skin and providing a more precise estimate, particularly for smaller testicular volumes [24]. Additional tests have been proposed to help in distinguishing between CDGP and congenital HH (CCH) which include inhibin B, antimullerian hormone, basal gonadotropin (LH and FSH) levels, GnRH stimulation, or GnRH-agonist stimulation tests, and human chorionic gonadotropin stimulation tests [26,27].