[Endocrine and morphological investigation in undescended testis (author's transl)]

Determination of the basal and LH-RH-stimulated luteinizing hormone (LH) levels as well as testicular morphology in patients with surgically treated (n equals 112) and non-treated (n equal 96) undescended testes gave the following results: Unilateral of bilateral undescended testes are probably a form of primary, secondary or tertiary hypogonadism. In a high percentage abnormal basal and stimulated serum-LH values can be demonstrated. The testosterone values are within normal limits. The gonadal tissue damage in the abnormally situated testes of prepubertal boys seem to be congenital. With increasing duration of the malposition, particularly after the onset of puberty, a secondary tissue degeneration in the dystopic testis occurs. The damaging influence on the testicular tissue caused by the abnormal position seems to take place mostly at the end of prepuberty. A decrease in the number of spermatogonia in the tubuli of dystopic testes during the first 2 years of life is physiological. A surgical repositioning of the dystopic testis into the scrotum within the first 2 years of life is not indicated. Damage of gonadal tissue in the scrotal testis caused by the dystopic testis in unilateral maldescent could not be demonstrated. The optimal space for orchidopexy is between the third and fifth year of life.