IS Case 126: Neurofibromatosis Type I with left optic glioma
Imaging Sciences URMC 2008
Publication Date: 2009-05-20
The left optic nerve and the optic chiasm are thickened. There are multiple areas of T2 hyperintense signal intensity seen in the basal ganglia, thalami and cerebellar hemispheres. There is no significant abnormal enhancement in these lesions.
Also known as von Recklinghausen syndrome, neurofibromatosis type 1 (NF-1) is an inherited disease that results from a mutation of a gene on the long arm of chromosome 17 which encodes the protein neurofibromin. Neurofibromin is a negative regulator of the Ras oncogene. The typical pattern of inheritance is autosomal dominant but up to half of all cases arise due to spontaneous mutation.
Clinical manifestations of the disease include neurofibromas in the peripheral nervous system. Dermatological findings include flat pigmented lesions called cafe au lait spots and freckles in the axillae. Other manifestations include focal scoliosis or kyphosis, bowing of long bones with pseudoarthrosis, malformation of facial bones, and unilateral overgrowth of limb.
Within the brain, the common findings of NF-1 are optic gliomas and so called "unidentified bright objects" (UBOs) which are foci of increased T2 signal in the brain that can occur in the pons, midbrain, globus pallidus, thalamus, and optic radiations. In this patient with known NF-1, there is asymmetric thickening of the optic chiasm and the left optic nerve. There are also multiple UBOs in the basal ganglia and thalami bilaterally.
- Castillo M. The Core Curriculum: Neuroradiology. 1st ed. Lippincott Williams & Wilkins. 2002.