Endocrine tests in phenotypic children with bilateral impalpable testes can reliably predict "congenital" anorchism.

Congenital anorchism is a rare condition. Bilateral impa-pable undescended testes are relatively common by comparison. Surgical exploration has been regarded as the final arbiter between anorchism and bilateral cryptorchism. Exploration has not proved completely reliable in making this differentiation. Endocrine studies, particularly the human chorionic gonadotropin (HCG) stimulation test together with measurements of basal plasma gonadotropins, can reliably exclude "functioning" testicular tissue. Eleven fully evaluated and operated cases support this contention. In the specific clinical setting of a normal phenotypic male child with a 46XY karyotype and no müllerian structures palpable on rectal examination, nonfunctioning testes on endocrine testing means congenital anorchism and surgical confirmation is unnecessary. In contradistinction, a positive HCG test would appear to mandate through and extensive surgical exploration.