CASE 1752 Published on 23.11.2002
0

Lipomatous meningioma

Section

Neuroradiology

Case Type

Clinical Cases

Authors

S. Cakirer

Connected authors
Patient

58 years, female

Categories
No Area of Interest ; Imaging Technique MR, MR
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Clinical History
The patient presented with severe headache.
Imaging Findings
The patient presented with severe headache. Cranial MRI was performed on a 1.5T MRI scanner, with SE T1-weighted, FSE T2-weighted, fat-suppressed SE T1-weighted, and post-gadolinium SE T1-weighted images in three planes.

A dura-based left parafalcian mass was detected with heterogeneous hyperintense components on T1- and T2-weighted images; the high signal intensity of the mass ceased on fat-suppressed images. The mass enhanced with IV gadolinium heterogeneously, and a dural tail reaction was detected at the dural base of the mass. The mass was surgically removed with the resultant diagnosis of lipomatous meningioma.

Discussion
Meningiomas are the most common intracranial extra-axial tumours. They are usually benign slowly growing neoplasms, however they may rarely reveal malignant behaviour. They are well-circumscribed dural-based lesions. They may cause compression of adjacent brain parenchyma, encasement of arteries, and compression of dural venous sinuses.

The most common locations for meningiomas can be listed as the parasagittal area, convexity, sphenoid ridge, parasellar area, posterior fossa, optic nerve sheath, and intraventricular region. They are usually isointense with cortical grey matter on all MRI sequences, with prominent gadolinium enhancement. Calcification is a frequently detected characteristic of the lesions. Necrosis, cysts, and haemorrhage may be associated in around 25% of the masses. A dural tail reaction, characterised by thickened dura tapering away from the tumour, is characteristic, but not pathognomonic for meningiomas.

Lipomatous meningiomas are relatively rare benign tumours that are characterised either by an admixture of mature adipocytes and meningioma or the production of lipids by neoplastic meningothelial cells assuming a lipoblast-like appearance. The lipomatous changes are thought to appear as a result of metaplastic changes of meningothelial cells. The signal intensity of lipomatous meningiomas is heterogeneous, but hyperintense components are detected on both T1- and T2-weighted images secondary to the presence of lipid.

Differential Diagnosis List
Lipomatous meningioma
Final Diagnosis
Lipomatous meningioma
Case information
URL: https://www.eurorad.org/case/1752
DOI: 10.1594/EURORAD/CASE.1752
ISSN: 1563-4086
Figure 1

Non-contrast-enhanced images

Non-contrast-enhanced images
Spin-echo T1-weighted axial image reveals a dura-based left parafalcian mass (arrow) that has heterogeneous hyperintense components.
Non-contrast-enhanced images
Fast spin-echo T2-weighted axial image reveals a dura-based left parafalcian mass (arrow) that has heterogeneous hyperintense components.
Non-contrast-enhanced images
Fat-suppressed spin-echo T1-weighted axial image shows the cessation of high signal intensity (arrow) on fat-suppressed sequence.
Figure 2

Contrast-enhanced images

Contrast-enhanced images
Post-gadolinium spin-echo T1-weighted axial image shows the intense heterogeneous contrast enhancement of the extra-axial mass with thickened falx cerebri (arrow).
Contrast-enhanced images
Post-gadolinium spin-echo T1-weighted coronal image shows the intense heterogeneous contrast enhancement of the extra-axial mass with thickened falx cerebri (arrow).