This patient presented with gradual decrease in vision, and partial excision confirmed a ganglioglioma of the optic nerve.
Gangliogliomas are a low grade tumour (WHO Grade I or II) which typically occur in the temporal lobes of young patients and present with temporal lobe epilepsy. 80% of cases are found in <30 year of age, however they have been reported at all ages. Following complete resection, prognosis is excellent and 80% are seizure free.

They demonstrate 3 types of growth pattern;
1. Circumscribed cyst with enhancing mural nodule (most common)
2. Solid mass with expands gyrus
3. Diffuse infiltrating mass (uncommon)

Calcification is common (35-50%), and enhancement is variable, sometimes extending beyond the nodule into the wall of cyst.
They are often associated with cortical dysplasia, and have been reported in association with DNETs, oligodendrogliomas and even tanycytic ependymomas. Anaplastic varients (WHO Grade III) and malignant degeneration into GBM-like tumours (WHO Grade IV) is rare.
For many more images of this case as well as histology report please visit here.

– Diagnostic Imaging: BRAIN by Osborn

Credit: Dr Frank Gaillard