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

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.