The testicle may be absent on one or both sides, while the vesiculse seminales and vasa deferentia are perfect. Or the vas deferens may be deficient while the testis is well developed.
Imperfect descent of the testis, or Cryptorchismus, is a very frequent and important condition. The descent of the testis occurs normally before birth, but in a considerable number of cases the organ has not yet appeared externally at birth. In the majority of such cases it comes down within the first week, but it is sometimes delayed for months or a year, or even till puberty. When thus delayed the descent is very often imperfect, so that the gland remains in the inguinal canal or at the ring. On the other hand, the testis may be retained throughout life in the abdomen. The testicle retained in the abdomen or on the way down is usually imperfectly developed, and although apparently of normal size, it does not generally contain spermatozoa in its tubules. It is also more prone to Inflammation and to the Formation of tumours than the normally placed testis, especially when retained in the inguinal canal where it is exposed to external violence. Gangrene is also of occasional occurrence in a retained testicle. It may arise from inflammation occurring while the testis is in a restricted space, more especially in the groin, or it may result from torsion of the cord including its artery. When it is late of descending, the accompanying pouch of peritoneum, which forms the tunica vaginalis, is apt to remain open and so to induce a Congenital hernia.
Besides these congenital misplacements, we may have the testis descending into the crural canal, or into the perineum.