CASE 13379 Published on 06.02.2016

Gliomatosis Cerebri: A Ghost in the Brain.

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Anastasia Zikou, Georgia Mouka, Vasileios Xydis, Maria Ι Argyropoulou.

Department of Clinical Radiology, Medical School of Ioannina, Greece.
Email: anzikou@cc.uoi.gr
Patient

65 years, male

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR-Spectroscopy, MR, MR-Diffusion/Perfusion
Clinical History
A 65-year-old male with a first episode of seizures without any medical or surgical history except behavioural and mental changes the last months. The electroencephalogram revealed waveforms compatible with frontal and temporal lobe epilepsy.
Imaging Findings
A brain-MRI revealed on FLAIR and T2-weighted sequences (fig. 1-2) diffuse hyperintense lesions in the left temporal, parietal and frontal lobes, the corpus callosum, the anterior ligament and the left cerebral peduncle. A lack of differentiation between gray and white matter was observed on T1 weighted images and no enhancement was seen after iv contrast administration (fig. 3). Perfusion maps showed normal or low r-CBV (fig. 4). DTI maps showed increased ADC values while the FA-maps revealed enlargement but normal directionality of the white matter tracts (fig. 5-6). MR-spectroscopy showed elevated ratio Cho/ NAA: 1.00 and marked elevation of myoinositol (fig. 7-8). Τhe above imaging findings were compatible with Gliomatosis cerebri (GC). Brain biopsy disclosed GC.
Discussion
GC is a rare diffuse neoplastic process of the brain that carries a poor prognosis. The WHO defines it as a diffusely infiltrating glial neoplasm affecting at least three cerebral lobes, usually with bilateral involvement of the cerebral hemispheres and/or deep gray matter [1-3]. Histopathologically, it is characterized by infiltrating neoplastic astrocytic elements into the surrounding neuropil [4]. GC is not a homogeneous entity and can contain areas of WHO grade II or III tumours. GC may be clinically silent, or has little and nonspecific symptomatology (e.g. seizures, headache, visual disturbance, behavioral and mental changes). There is often an important discordance between clinical and imaging findings, while it appears as a very extensive process radiologically [1].
Two imaging subtypes have been identified: the classic subtype without a solid component (type I) and a second subtype with a solid component (type II). The underlying molecular pattern may be different in these categories. IDH1 mutations have been reported as more prevalent in type II GC [5-9]. MRI findings are important for a correct diagnosis. The characteristic hallmarks of the lesion are hypointensity in T1-weighted sequences and hyperintensity in T2-weighted and Flair sequences. A typical finding is the diffuse infiltration of the cortex with an enlargement of the cortical sulci and poor demarcation of the grey and white matter. After contrast administration, there is no enhancement. DWI shows no restricted diffusion. MR spectroscopy shows elevated Cho:NAA ratios and marked elevation of myoinositol. Perfusion MR shows low or normal rCBV values correlating with no vascular hyperplasia. GC diagnosis requires correlation of imaging and pathological signs, brain biopsy and histopathological examination are mandatory [10].
The optimal treatment for GC is unclear: surgery is of little benefit due to the extensive and diffuse infiltration from the disease. Radiotherapy is hazardous because of the extensive process necessitating a very large and thus dangerous brain exposition to irradiation. Therefore chemotherapy is considered as the first line treatment. GC has an extremely poor prognosis. Transformation into glioblastoma may occur a few years later. Median overall survival between 14.5 and 38.4 months reported in the literature [1-3].
Differential Diagnosis List
Gliomatosis Cerebri.
• Progressive multifocal leukoencephalopathy
• Multicentric glioblastomas
Final Diagnosis
Gliomatosis Cerebri.
Case information
URL: https://www.eurorad.org/case/13379
DOI: 10.1594/EURORAD/CASE.13379
ISSN: 1563-4086
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