Unusual Meningioma

Unusual Meningioma

This 50-year-old presented with progressively worsening headaches. MRI demonstrated a T2 hyperintense heterogeneously enhancing 2.5 cm lesion centered in the right frontal lobe. At the time of neurosurgery the lesion was noted be dural-based and was gross totally resected.

The tumor cells showed patchy membranous staining for EMA, absence of staining for GFAP, PAX8, cytokeratin and inhibin, and a low proliferative fraction as indicated by Ki67. CD68 immunohistochemical stain highlighted occasional scattered lesional cells. The lesion appeared to be dural based and no brain invasion was seen.

What is your diagnosis based on Figures #1 – #3?

A. Hemangioblastoma

B. Meningioma

C. Metastatic RCC

D. Astrocytoma

The correct answer is B. Meningioma. The pathologic alterations are consistent with the presence of a WHO grade 1 meningioma with “lipidized” cells (lipidized meningioma).

References/Additional Reading:

• Lapolla P, Familiari P, Zancana G, Bruzzaniti P, Chen R, Li X, Familiari G, Santoro A. Lipomatous Meningioma: Clinical-Pathological Findings, Imaging Characterisation and Correlations of a Rare Type of Meningioma. In Vivo. 2021 Nov-Dec;35(6):3031-3037. doi: 10.21873/invivo.12598. PMID: 34697134; PMCID: PMC8627722.
• Roncaroli F, Scheithauer BW, Laeng RH, Cenacchi G, Abell-Aleff P, Moschopulos M. Lipomatous meningioma: a clinicopathologic study of 18 cases with special reference to the issue of metaplasia. Am J Surg Pathol. 2001 Jun;25(6):769-75. doi: 10.1097/00000478-200106000-00008. PMID: 11395554.
• Kepes JJ. Lipidized meningothelial tumor cells in “xanthomatous” meningioma express macrophage antigen. J Neuropathol Exp Neurol. 1994 Jul;53(4):384-8. doi: 10.1097/00005072-199407000-00010. PMID: 8021712.