Immunohistochemical findings of multiple ossified en plaque meningiomas in the thoracic spine

Abstract

We describe a 76-year-old woman who presented with painful muscle weakness and numbness in both legs secondary to grossly ossified meningiomas at the T8 and T11–T12 vertebral levels. Midline durotomy followed by en bloc excision of the tumours, together with partial resection of the dura mater and the arachnoid, was performed. Histopathological examination showed both tumours consisted of three different histological patterns: psammomatous, fibrous, and metaplastic subtypes. Immunostaining for bone morphogenetic protein-2 and vascular endothelial growth factor was significantly positive in the areas surrounding mature bone tissues in the metaplastic and psammomatous subtypes.

Introduction

Meningioma of the spinal cord is a common intradural extramedullary neoplasm, comprising 25–43% of all spinal cord tumours that emanate from the meninges, with the highest frequency from the anterolateral aspect of the arachnoid.[1], [2] Psammomatous meningothelial meningioma is an infrequent lesion that appears as a calcified mass on plain radiograph or CT scan.[3], [4], [5] The ossified spinal meningioma en plaque[3], [6] is extremely rare, with a reported incidence of 1–5% of all spinal meningiomas.[3], [7] However, the mechanism responsible for the ossification process remains poorly understood. We describe a patient with multiple ossified spinal en plaque meningiomas, and report the immunohistochemical findings.