Lisch nodules: a diagnostic sign for Von Recklinghausen's neurofibromatosis.

It was in 1882 that Von Recklinghausen described the components of neurofibromatosis. This disease represents one of the most common of the phakomatoses occurring in approximately 1 out of every 3,000 live births. The genetic inheritance is that of autosomal dominant with variable expressivity. Cafe-au-lait spots, axillary freckling, and numerous tumors which are derived from the Schwann cells of the peripheral nerves and neurofibromas of the central nervous system characterize this disease. Although it is congenital, signs and symptoms of Von Recklinghausen's may not become apparent until late childhood or early adulthood. Approximately 33% of all cases of Von Recklinghausen's disease are discovered accidentally on routine examination.