CT IMAGING IN ADULTS WITH NEUROFIBROMATOSIS-1 - FREQUENT ASYMPTOMATICPLEXIFORM LESIONS

Objective: The authors examined the incidence and radiologic character istics of plexiform neurofibromas in neurofibromatosis-1 (NF-1) to def ine a cohort at greatest risk for malignant nerve-sheath tumors. Backg round: Plexiform neurofibromas are a frequent complication of NF-1. Th ey can impair function, produce disfigurement, and be the site for the development of malignant nerve-sheath tumors. The incidence and natur al history of plexiform neurofibromas is unknown, Methods: CT imaging of the chest, abdomen, and pelvis was performed in 91 of 125 consecuti ve adults (age, greater than or equal to 16 years) with NF-1. Results: Twenty percent of patients had plexiform neurofibromas of the chest i n the paraspinal, mediastinal, or supraclavicular area. Approximately 40% of patients had abnormal abdominal/pelvic scans. The paraspinal, s acral plexus, sciatic notch, and perirectal regions were the most comm on sites. Most plexiform neurofibromas were asymptomatic. Imaging also revealed a number of tumors, including malignant nerve-sheath tumors, adrenal tumors, carcinoids, and schwannomas. Conclusions: The frequen cy of plexiform lesions and other tumors in NF-1 indicates that clinic ians should monitor young adults carefully; however, imaging character istics alone cannot reliably distinguish benign from malignant lesions .