Is there a relationship with anomalous insertions of the distal gubernaculum testis and testicular ectopia? Analysis in human fetuses and patients with cryptorchidism

Purpose: One of the most accepted theories for explaining testicular ectopia is the existence of multiple distal insertions of the gubernaculum testis. We studied the distal insertions of the gubernaculum in human fetuses and patients with cryptorchidism. Materials and Methods: We studied 326 gubernacula in 163 human fetuses at 10 to 35 weeks of gestation and 133 gubernacula in 101 patients with cryptorchidism (mean age 6.4 years). With the aid of a stereoscopic microscope (2.5 x magnification), the existence of distal insertions of the gubernaculum was investigated. Fisher's exact test was used to compare the 2 study populations. Results: Of 326 fetal testes 224 (68.7%) were abdominal, 45 (13.8%) inguinal and 55 (16.9%) scrotal. In 1 fetus (0.6%) at 23 weeks of gestation both testes and both gubernacula were absent. Among 133 cryptorchid testes 17 (12.8%) were abdominal, 92 (69.2%) inguinal, 24 (18%) high scrotal and 3 (2.3%) evanescent. Of 324 fetal gubernacula present we found only 2 anomalous distal insertions in the pubopenile region (0.6%). All other distal insertions (99.4%) were at the usual location. Of 133 cryptorchid testes the 3 evanescent testes did not present visible gubernacula. Among 130 gubernacula analyzed all were inserted in the scrotal region. Conclusions: The existence of anomalous insertions at the distal portion of the gubernaculum is rare in human fetuses and patients with cryptorchidism.