Neurofibromatosis type 1 presenting with plexiform neurofibromas in two patients: MRI features.

Neurofibromatosis type 1 (NF1), also known as peripheral neurofibromatosis or von Recklinghausen's disease, is one of the most common genetic disorders. It is inherited in an autosomal dominant pattern. Multiple cutaneous neurofibromas are hallmark lesions of NF1. Localized and plexiform neurofibromas of the paraspinal and sacral region are the most common abdominal neoplasms in NF1. Herein, we report two patients with a known history of NF1 presenting with multiple, extensive localized and plexiform neurofibromas. We describe the important distinguishing features of these tumors as seen on magnetic resonance imaging (MRI), including very bright signal intensity and target sign on T2 weighted images.