Prenatal ultrasound abnormalities in a patient with generalized neurofibromatosis type 1.

We describe a patient with an unusual neonatal disseminated form of neurofibromatosis (NF1). Prenatal ultrasound studies, at 35 weeks of gestation, revealed ambiguous external genitalia, an increased biparietal diameter and a decreased growth of long bones. Postnatal examination displayed generalized neurofibromatosis, with perineal, thoracic and spinal cord invasion by tumors. Spinal cord compression was responsible for paraparesis. The child died of a pulmonary infection at five years of age. No previous report of such prenatal abnormalities has been described. Genetic counselling is difficult because of the variable expression of the illness.