Ultrasonographic diagnosis of non-palpable Sertoli cell tumours in infertile dogs

Three previously fertile dogs were examined with a history of recent infertility. Semen evaluation revealed marked spermatozoal abnormalities, including lesions of the mid-piece region, poor spermatozoal motility and a low total spermatozoal output. The mean number of live normal spermatozoa was 21·1 ± 17·4 × 10⁶ spermatozoa. Examination of the testes with diagnostic B-mode ultrasound demonstrated solitary mass lesions which in each case were not palpable. Plasma oestrogen concentrations were elevated (mean, 43·0 ± 8·s 5 pg/ml), and histologically the masses were shown to be Sertoli cell tumours. Several months after unilateral orchidectomy there was an increase in the percentage of normal spermatozoa and an increase in the spermatozoal motility and total spermatozoal output. The mean number of live normal spermatozoa was 149·8 ± 22·9 × 10⁶ spermatozoa and all the dogs subsequently returned to fertility. Ultrasonographic examination of the testes should be considered part of the routine investigation of the male reproductive tract.