Male pseudohermaphroditism secondary to an abnormality in Leydig cell differentiation.

We present the first case of a prepubertal male with an abnormality in Leydig cell differentiation resulting in male pseudohermaphroditism. There was no plasma androgen response to im administration of hCG. Leydig cells were not apparently by either light or electron microscopy in tissue obtained from a biopsy of the right testis 96 h after the last dose of hCG. In addition, LH-hCG saturation analyses performed on membrane preparations from the testicular tissue revealed no binding. An expanded classification for male pseudohermaphroditism is presented.