Purpose: The etiology of the ascending testis is controversial. We propose that ascending testis, defined as a testis previously thought to be descended and later noted to be out of the scrotum, is due to mild hypogonadotropic hypogonadism affecting both testes. The diagnosis of these low types of true undescended testes is difficult to make clinically in children since they are frequently confused with retractile testes. In this study we compared testicular biopsies in a group of boys with ascending testes with those in boys who had an undescended testis since birth (primary undescended testis).
Materials and methods: Between 1985 and 1995, 91 patients with ascending testes underwent orchiopexy and bilateral testis biopsy. The total germ cell count, processus vaginalis status, age at surgery and whether followup was done by a pediatrician or pediatric urologist were compared in patients with ascending and unilateral primary undescended testes.
Results: The total germ cell count was similar in the undescended and the contralateral descended testis in patients with ascending and primary undescended testes. The processus vaginalis was more likely to be closed in ascending testes (57% versus 36%, p = 0.0001). Age at surgery and the total germ cell count were similar in patients followed by pediatricians and pediatric urologists.
Conclusions: The ascending testis has the same germ cell count as the primary undescended testis. Yearly followup by the primary care physician is recommended for patients with retractile testes.