Clear-cell meningioma: An uncommon aggressive variant of meningioma.

Abstract

Background: Clear-cell meningioma is a rare subtype, representing 0.2-0.8% of all meningiomas. It is classified as grade 2 according to World Health Organization (WHO) classification due to its aggressive clinical course. Morphologically, it can mimic other clear-cell tumors arising in the central nervous system, each having different clinical behavior, therapeutic protocol, and prognostic outcome.

Aim: This study aims to describe clinicopathological characteristics of clear-cell meningioma and to discuss the histomorphological features and differential diagnosis.

Materials and methods: The demographic, clinical, radiological, histopathological features, and follow-up of the patients were recorded and analyzed.

Results: Clear-cell meningioma constituted 1.3% of all meningiomas. The age of the patients ranged from 16-46 years (mean age - 27 years), with a slight female predominance. Follow-up varied from six months to six years. Recurrence was noted in four patients while three patients died. Histopathology revealed sheets of clear cells with prominent blocky interstitial and perivascular collagen deposition. Focal vague whorl formation and occasional intranuclear inclusions could be identified on careful search. Conventional meningothelial areas or typical psammoma bodies were not seen.

Conclusion: Clear-cell meningioma is a rare subtype of meningioma with aggressive behavior. The presence of blocky collagen, a careful search for whorl formation, and intranuclear inclusions are helpful in approaching the correct diagnosis. An interdisciplinary approach by correlating the clinical, radiological, and histological features can enhance the accuracy of diagnosis.