Brainstem glioma

Clinical History

A 22-year-old woman was admitted to the hospital with gait disturbance, headache and weakness of the limb for a week.
Neurological examination revealed a cerebellar ataxia with dysarthria, paresthesis and left hemibody paralysis.
No history of fever or cancer.

Imaging Findings

CT examination showed a pontic hypodense lesion with a marked mass effect over the fourth ventricle and prepontine citern (Fig. 1)
MRI showed a limited pontic lesion with hypointense signal on T1-weighted images (Fig. 2) and a hyperintense lesion on T2-weighted images (Fig. 3), with a peripherical enhancement after gadolinium administration (Fig. 4).
There was no abnormal supratentorial signal.
A stereotactic brain biopsy was performed, which led to the diagnosis of high malignancy glial tumour.
The treatment was only radiation.

Discussion

The clinical presentation of brainstem gliomas is often non-specific and misleading. Radiological imaging is imperative to demonstrate a brainstem lesion [1].
The majority of brainstem gliomas occurs in the pons, where they are more likely to be high-grade and have a poor prognosis [2]. These tumours progress rapidly, invading adjacent structures and resulting in an average survival of less than 1 year [3]. Due to the accelerated growth rate, symptoms of high-grade pontine gliomas are usually short in duration and rapidly progressive in severity.
Radiographic imaging is often the preferred method of diagnosis and classification rather than histological examination.
Computed tomography (CT) of high-grade pontine gliomas typically shows a hypodense or isodense lesion; MRI shows a hypointense lesion on T1-weighted images and a hyperintense lesion on T2-weighted images. Rapid diffusion MRI, thallium single photon emission computed tomography (SPECT) [4] and positron emission tomography (PET) [5] are emerging as potentially superior imaging techniques for brainstem lesions.
Misdiagnoses associated with brainstem gliomas are reported in the literature. This is in part due to the common symptomatology seen in various lesions of the central nervous system.
Badhe et al. performed a retrospective analysis of 45 cases of brainstem gliomas [6]. Fifteen percent were grade IV; most were located in the pons (55.55%). Pontine tumours were more likely to invade superiorly and laterally into adjacent structures than tumours of the medulla or midbrain.
Randomized clinical trials combining surgery, irradiation and chemotherapy are suggested. Patients treated with large radiation fields had a better overall survival rate than patients treated with medium or small fields [7].

Differential Diagnosis List

Final Diagnosis

Brainstem glioma

URL:	https://www.eurorad.org/case/13562
DOI:	10.1594/EURORAD/CASE.13562
ISSN:	1563-4086