Prevalence of the vanishing testis in boys with a unilateral impalpable testis: is the side of presentation significant?

A total of 208 boys with a unilateral impalpable testis and a contralateral descended testis was studied to correlate the probability of finding blind-ending vas and vessels (vanishing testis) with the side of presentation of the impalpable testis. Of 142 boys with a left impalpable testis 93 (65%) had a vanishing testis and of 66 boys with a right impalpable testis 38 (58%) had a vanishing testis (p < 0.28). These data indicate that impalpable and vanishing testes are more likely to occur on the left side in boys with a unilateral impalpable testis but the likelihood of having a vanishing testis is similar regardless of the side of presentation.