Myotonic dystrophy presenting as male infertility: a case report.

A 28-year-old man presented with azoospermia, low plasma testosterone levels, and an elevated follicle stimulating hormone (FSH) concentration. Bilateral testicular biopsies revealed tubular atrophy with normal-appearing Leydig cells. One year later, symptoms and signs consistent with myotonic dystrophy (MyD) were noted. The rarity of male hypogonadism preceding the neurological manifestations of MyD is stressed.