Cryptorchidism Cryptorchidism is distinct from monorchism, the condition of having only one testicle. Though the condition may occur on one or both sides, it more commonly affects the right testis. A testis absent from the normal scrotal position may be: About two-thirds of cases without other abnormalities are unilateral; most of the other third involve both testes. In 90% of cases, an undescended testis can be felt in the inguinal canal. In a small minority of cases, missing testes may be found in the abdomen or appear to be nonexistent (truly "hidden"). Undescended testes are associated with reduced fertility, increased risk
Tunica vaginalis Tunica vaginalis The tunica vaginalis is the pouch of serous membrane that covers the testes. It is derived from the vaginal process of the peritoneum, which in the fetus precedes the descent of the testes from the abdomen into the scrotum. After its descent, that portion of the pouch which extends from the abdominal inguinal ring to near the upper part of the gland becomes obliterated; the lower portion remains as a shut sac, which invests the surface of each testis, and is reflected on to the internal surface of the scrotum; hence it may be described as consisting of