The incidence of carcinoma in situ in postpubertal undescended testis.

In a retrospective study of 32 adult males undergoing "preventive" orchiectomy for unilateral undescended testis the average age of the patients at the time of orchiectomy was 28.3 years (range 16-63). Macroscopically, all the testes were atrophic and there was no evidence of tumour. In all surgically removed testes histological examination showed atrophied germinative epithelium and absence of spermatogenesis. In one patient, aged 16, an obvious carcinoma in situ was identified. In another 3 patients, aged 18, 19 and 29, atypical germ cells were found. Unilateral undescended testis in postpubertal patients should be treated by orchiectomy instead of orchiopexy.