Case History

MR – Axial T2 and postgadolinium T1 images demonstrate mass with vasogenic edema to the right of the 4th ventricle (biopsy proven astrocytoma), occlusion of the left internal carotid artery with chronic ischemia, and plexiform neurofibromas of the left orbit, cavernous sinus, face and scalp.

Neurofibromatosis is the most common of the phakomatoses with an occurrence of 1 in 4000. Most cases are inherited but new mutations account for a large number of cases. The gene encoding neurofibromin on chormosome 17q11.2 results in inadequate suppression of the Ras oncoprotein and an increase incidence of tumors.

Plexiform neurofibromas occur in 27% of patients with NF1 but are unusual in children under the age of 10 years. Plexiform neurofibromas are mass-like and can grow rapidly. Malignant degeneration occurs in upto one-third.

Vasculopathy associated with NF is related to intimal hypertrophy and fragmentation of the media. Aneurysms and stenoses are found in about 2% of patients. Moya-moya, renal artery hypertension and middle aortic syndrome can be seen.

Neuroglial hamartomas are commonly encountered. The optic pathway glioma is characteristic. Other intracranial neoplasms include astrocytomas and ependymomas.

Neurofibromatosis, Multiple Cranial Manifestations