De novo malignant optic chiasm glioma with initial clinical response to steroids

Abstract

Malignant optic nerve glioma (MONG) is a rare but uniformly fatal disease that remains poorly understood. We describe a notable case of this rare disease occurring in the optic chiasm. Normal brain imaging and normal ophthalmic examination two years prior to diagnosis provide evidence for de novo genesis of MONG in our patient. Early response to steroids highlights the degree to which MONG can initially mimic inflammatory optic neuropathies and chiasmal syndromes. Our case also demonstrates a poor outcome with MONG even with current advanced therapy for glioblastoma including radiotherapy plus concomitant and adjuvant temozolomide (the EORTC/NCIC regimen) and bevacizumab.

FIGURE 1

Visual field at time of presentation. Goldmann kinetic perimetry showing bitemporal paracentral scotomas respecting midline with sparing of both the nasal and temporal periphery.

FIGURE 2

MR images of malignant chiasmal glioma. Unremarkable postcontrast T1 coronal (A) and axial (B) brain MR imaging obtained 2 years prior to onset of symptoms. Postcontrast T1 coronal (C) and axial (D) orbital MR imaging obtained at the time of symptom onset showing diffuse enhancement of the chiasm with extension into the proximal optic nerves and tracts bilaterally. Postcontrast T1 coronal (E) and axial (F) orbital MR imaging obtained 5 months after initial diagnosis showing progressive necrosis and enlargement of the malignant glioma with extension into the optic nerves and tract.

FIGURE 3

Right optic nerve histological evaluation. (A) Haematoxylin-eosin stain showing highly cellular neoplasm (100×); (B) GFAP positivity suggesting glial differentiation (200×); (C) elevated staining of Ki67 proliferation marker (400×); and (D) p53 tumour marker (200×).