THE VANISHING TESTIS - ANATOMICAL AND HISTOLOGICAL-FINDINGS

Objectives: To review anatomical and histological findings in 105 vani shing testes. Methods: Records of 2,509 boys with 3,064 cryptorchid te stes treated at our hospital between 1969 and 1995 were reviewed. Resu lts: 691 (23%) testes were clinically impalpable. Exploration in 691 i mpalpable testes revealed absent testis in 144 (21%). In 39 (27%) of t he 144 absent testes, there was complete agenesis of testis along with the epididymis and vas deferens whereas 105 (73%) were associated wit h blind-ending cord structures - the vanishing testis. The site of bli nd-ending cord structures in 105 vanishing testes was intra-abdominal in 22 (21%), inguinal canal in 62 (59%), superficial inguinal ring in 19 (18%) and scrotum in 2 (2%). Histological information was available in 47 vanishing testes and revealed vas, epididymis, or both in 32 (6 8%), fibrous/vascular tissue in 11 (23%) and testicular cords in 4 (9% ). Dystrophic calcification and/or haemosiderin were present in 7 (15% ). Conclusions: Our data show that the incidence of vanishing testis i n boys with non-palpable testes is over twice the incidence of testicu lar agenesis. The most common site of blind-ending cord structures is distal to the internal inguinal ring. The finding of viable testicular tissue at the end of the attenuated cord structures in 4 of our patie nts, and also reported in other series, suggests that inguinal explora tion should be carried out in all patients who on laparoscopy are foun d to have cord structures entering the internal ring.