Usefulness of screening investigations in neurofibromatosis type 1 - A study of 152 patients

Objective: To evaluate the usefulness of screening investigations in patients with neurofibromatosis type 1 (NF1). Design: Clinical and screening data were retrospectively collected from a case series of patients with NF1. Screening investigations included an opthalmologic consultation, chest x-ray film, abdominal ultrasonography, cerebral imaging, and analysis of urinary catecholamine levels. Clinical features and complications of patients with NF1 were compared with those of the Neurofibromatoses Institute Clinical Research Program and of the Southeast Wales study patients. Setting: Ambulatory care in a referral center. Patients: Between 1988 and 1992, 152 patients classified as having NF1 according to the criteria of the National Institutes of Health Consensus Development Conference Statement were studied. Main Outcome Measure: Complications requiring therapeutic action detected using screening investigations vs clinical examination. Results: Systemic chest x-ray films were taken of 134 patients, and intrathoracic nodules thought to be neurofibromas were discovered in 2 patients. Ninety-three asymptomatic patients had cerebral imaging performed, which showed optic pathway glioma in 12 patients. Abdominal ultrasonography was performed on 62 asymptomatic patients, results of which showed internal neurofibromas in 4 patients. In 2 of these patients, abdominal surgery was performed. Eighty-three patients without hypertension had 24-hour urinary specific catecholamine levels analyzed, which were within the normal range. Clinical features and complications were not different from other large clinical studies. Nearly 400 systematic investigations were performed without clinical orientation, detecting 21 abnormalities. In only 2 cases, these discoveries led to therapeutic action. On the other hand, 22 complications requiring treatment were detected by clinical examination. Conclusion: Clinical follow-up seems to be more beneficial than systematic investigations in patients with NF1.