CASE 12629 Published on 27.03.2015
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ΜR spectroscopy findings of a trigonal intraventricular meningioma

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Anastasia Zikou, Vasiliki Mouka, Vassilios Gkogkos, Loukas G Astrakas, Vassilios Xydis, Maria Ι Argyropoulou.

Department of Clinical Radiology, Medical School of Ioannina, Greece.
e-mail: anzikou@cc.uoi.gr
Connected authors
Patient

69 years, male

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR, MR-Spectroscopy
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Clinical History
A 69-year old male patient presented with a history of long-standing headaches.
Imaging Findings
A brain MRI revealed a large, inhomogeneous intraventricular mass, located at the trigone of the left lateral ventricle. On T1 and T2-weighted images the mass was in isosignal to the cortex and showed an intense, inhomogeneous enhancement after the intravenous contrast administration. Some cystic areas were recognized within the mass (Fig. 1, 2). A short TE (23ms) proton MR spectroscopy (MRS) was performed using a 2 x 2 x 2 cm voxel located within the mass. MRS revealed high levels of choline, the presence of alanine as a doublet at 1.3 ppm and 1.5 ppm, absence of creatine and NAA, as well as increased levels of glutathione, glutamine and glutamate (Fig. 3).
Discussion
Intraventicular meningiomas, although rare (0.7% of all meningiomas), represent the more common intraventicular neoplasms in the adult population. These tumours occur in patients older than 30 years, with a 2:1 female to male ratio. They are believed to arise from the arachnoidal cap cells trapped within the choroid plexus, the tela choroidea or the velum interpositum. The trigone of the lateral ventricle is the most common site, with a predilection for the left side. Less commonly, they might be located in the third ventricle and rarely in the fourth. As for the most of the intracranial meningiomas, the intraventricular ones appear in isosignal to the grey matter in pre-contrast images and enhance intensively after contrast administration. Cyst-like regions, either due to cystic degeneration or necrosis, may occasionally be noted [1]. The most common appearance on MRS is high choline peak with decreased or absent NAA and creatine and variable amounts of lactate, lipids and alanine [2, 3]. Increased glutathione, glutamate and glutamine (Glx) levels have also been observed in meningiomas [4]. Overall, the simultaneous presence of alanine, elevated glutathione and Glx, minimal lipids [3] with the combination of a high ratio of alanine to creatine and glutamate to creatine [5, 6] on proton MRS seem to be reliable findings to discriminate between meningiomas and other tumours.
Differential Diagnosis List
Intraventricular meningioma
Choroid plexus papilloma
Choroid plexus carcinoma
Choroid plexus metastasis
Glioma
Ependymoma
Final Diagnosis
Intraventricular meningioma
Case information
URL: https://www.eurorad.org/case/12629
DOI: 10.1594/EURORAD/CASE.12629
ISSN: 1563-4086
Figure 1

Brain MRI

Brain MRI
Axial, T2w-images reveal a large intraventricular mass (straight arrows). Cystic areas, with high signal intensity on T2w-images, are seen within the mass (curved arrows).
Figure 2

Brain MRI

Brain MRI
Axial, T1w-images after the iv contrast administration reveal the inhomogeneous enhancement of the mass (straight arrows). The cystic areas appear with low signal intensity (curved arrows).
Figure 3

Spectroscopy

Spectroscopy
Spectrum analysis consists of high levels of choline, the presence of alanine as a doublet at 1.3 ppm and 1.5 ppm, absence of creatine and NAA, as well as increased levels of glutathione, glutamine and glutamate.