Glioblastoma Multiforme in a Patient with Isolated Hemimegalencephaly

Abstract

We present an exceptional case of a patient with hemimegalencephaly and secondary intractable epilepsy treated with vagus nerve stimulation (VNS) and subsequent glioblastoma development in the hemimegalencephalic hemisphere 6 years after surgery. VNS (at age 18 years) led to a 60% reduction of intractable seizures. However, symptoms of intracranial hypertension suddenly occurred 6 years after surgery. A computed tomography scan revealed a brain tumor in the hemimegalencephalic hemisphere. Pathologic examination confirmed glioblastoma multiforme. The genetic background of hemimegalencephaly is discussed here, with attention paid to the available data about the malignant transformation of malformations of cortical development (MCDs). The case points to the need for adequate clinical and radiologic follow-up care for patients with MCDs including hemimegalencephaly.

Keywords: epilepsy; glioblastoma multiforme; hemimegalencephaly; malformations of cortical development.

Fig. 1

Magnetic resonance imaging study (age 18 years). Isolated right hemisphere hemimegalencephaly. (A) Diffuse cortical thickening with some blurring of the cortical-subcortical border, irregular white matter hyperintensity, and right callosal body dysgenesis. (B) Extent of cortical involvement in the area corresponding to the brain tumor; note marked cranial asymmetry.

Fig. 2

Computed tomography image (age 24 years). Extensive right frontal tumor with postcontrast enhancement and central hypodensity. (A) Marked midline shift. (B) Extensive vascularity and cortical involvement.

Fig. 3

Necrotizing glioblastoma with a high degree of anaplasia (original magnification ×100; hematoxylin and eosin staining).