Optic pathway glioma with neurofibromatosis type I
Loading Stack -
0 images remaining
A supra-sellar mass lesion centered upon the optic chiasm is noted. It measures about 2x2.8x0.7 cm along its maximum AP, TS and CC dimensions respectively. It is seen iso-intense to the brain parenchyma in T1 WIs and T2 with no appreciable enhancement in the post-contrast series. It is not surrounded by edema and exerts no significant mass effect.
There is diffuse uniform thickening of the right and to a much lesser extent left optic nerves with mild tortuosity of their courses.
Areas of altered signal intensity are seen involving the cerebellar hemispheres, medulla, pons, midbrain, both thalami, both internal capsules, both lentiform and caudate nuclei and occipital periventricular regions. They are inconspicuous in T1 and elicit high T2 and FLAIR signals with no appreciable post contrast enhancement. They are not surrounded by edema or exerting significant mass effect .There is marked contour bulge of the lower pontine anterior aspect.
Right cerebellar hemisphere enhancing lesion is seen. It measures about 8x8x8 mm along its maximum AP, TS and CC dimensions respectively. It is seen eliciting low T1, high T2 and FlAIR signals with homogenous post contrast enhancement. This lesion lies within one of the previously mentioned areas of abnormal signal intensity. This enhancement is worrisome and needs close follow up.
Partial agenesis of the splenium of corpus callosum.
Cavum septum pellucidum.
Prominent cortical sulci and extraaxial CSF spaces.
Hypertrophied nasopharyngeal soft tissue, likely of adenoid origin.
Optic pathway glioma has 3 broad types:
-Childhood benign tumors associated with NF1.
-Childhood benign tumors not associated with NF1.
-Adult tumors that are typically malignant.
-Best diagnostic tool: Fusiform optic nerve mass with variable posterior pathway involvement.
-Ranges from no enhancement to intense homogenous enhancement.
-Calcification is rare (unlike optic sheath meningioma).
-Bilateral intraorbital lesions indicate NF1.
-Associated neuroimaging findings if NF1 is present: Brain T2 foci, other CNS tumors, sphenoid dysplasia.
- Diagnostic Imaging Head and Neck, First edition