Magnetic resonance imaging of xanthomatous meningioma

A Rare Variant of Meningioma: Case Report and Review of Literature

Meningioma is a morphologically heterogeneous tumour arising from meningothelial cells that has been classified by the World Health Organization into 15 different histological types and graded into three types groups (Grade I, II, and III) based on the biological behavior. Metaplastic meningioma is a rare subtype of meningioma characterized by focal or widespread mesenchymal differentiation in the form of bone, cartilage, fat, or xanthomatous tissue elements. Xanthomatous meningioma is a subclass of metaplastic meningioma which is exceedingly rare. Only a few cases have been reported in the literature. Here, we report the case of a 44-year-old man, who presented with left sided weakness and was diagnosed as a case of xanthomatous meningioma.

Lipoblastic meningioma. Case report

We describe the case of a patient presenting a right parietal mass lesion with an heterogeneous aspect on computed tomography, with hyperdense contrast uptake areas and hypodense areas with fat density. The unusual aspect of the lesion prevented preoperative and intraoperative diagnosis. The final histopathological examination revealed a meningothelial neoplasia with adipose differentiation, characterizing a lipoblastic meningioma.

CT appearance of microcystic meningioma

Microcystic meningioma is an unusual variant, which has recently been proposed for inclusion in the WHO Classification of Central Nervous System Tumors. Its unique structure produces findings that may be confusing to radiologist and pathologist alike. A case is reported and the English language literature reviewed.

Development of fat within a meningioma

We report a tentorial meningioma containing fat. Multiple areas of fatty density or intensity in the tumour were seen on CT and MRI, which corresponded histologically to lipomatous components. CT 10 years previously had demonstrated a smaller tumour without evidence of fatty components. We found only five cases in the literature in which fatty density was demonstrated within a meningioma on CT and a lipomatous component histologically proved. Xanthomatous change, with lipid in tumour cells, causes decrease in density on CT, but not to the levels of fat. As both lipomatous components and xanthomatous change show similar intensity on MRI, CT can be helpful in differentiating these two conditions. To our knowledge, our case is the only one in which the advent of fatty tissue was confirmed during follow-up.