A boy with Leydig cell tumour and precocious puberty: ultrasonography as a diagnostic aid.

A 7 1/2 year-old boy developed pseudoprecocious puberty. The diagnosis of Leydig cell tumour was suggested by clinical and hormonal findings and greatly facilitated by ultrasonographic investigation of the testes. Surgical exploration was in keeping with the diagnosis and the tumour was removed. Orchidectomy was not necessary. It appears that ultrasonography may be very useful in diagnosing a testicular tumour. It facilitates surgical intervention since it permits localization of the lesion which is usually very small and limited to a small part of the testis, as in this case.