Clinical and cytogenetic studies in undescended testes.

168 boys and 2.5-16.8 years with unilateral or bilateral undescended testes or anorchia were studied. Retention was severe (canalicular or intraabdominal) in 1/4 and moderate in 3/4 of the cases. In unilateral retention, the volume of the scrotal testis was usually normal throughout childhood whereas pubertal testicular growth was delayed. In unilateral anorchia, the scrotal testis showed compensatory hypertrophy. In all age groups examined, the mean volume of the undescended testes was abnormally small. Undescended testes were accompanied by abnormalities of the epididymis in 3.6% of cases, of the ductus deferens in 7.8% and of the spermatic vessels in 8.3%. In anorchia such abnormalities were found regularly. Inguinal hernia accompanied 62.8% of the undescended testes and was most frequent in severe cases. Patients aged 8.0-9.9 years with unilateral undescended testis had advanced bone age. Cytogenic investigations of 167 patients revealed one case of Klinefelter's syndrome (47, XXY). Gonadotrophin treatment was tried in 50 patients and was succesful in 12. Surgical results were satisfactory in 86.1% of the operated testes.