Ossified spinal tumour in a 58-year-old woman with increasing paraparesis

Abstract

A 58-year-old woman presented to the Department of Neurosurgery, Santo Spirito Hospital, Rome, Italy for increasing paraparesis for almost 1 year. The MRI examination of dorsal spine detected an extramedullary expansive lesion at D6 soma level (Fig. 1a,b); the lesion showed a dural attachment and both plain and contrast-enhanced MRI features suggested a meningioma with areas of calcification.The lesion was completely removed with a posterior approach after D5 and D6 laminectomy.After surgery the patient started a rehabilitation therapy with a good functional improvement after 1 year. PATHOLOGICAL FINDINGSMacroscopically, the lesion was presented as a nodular mass, 1.5 cm in diameter, characterized by a hard texture typical of bone or calcified tissues. The specimen was decalcified in a chlorhydric and formic acid solution, routinely used for bone tissue decalcification, and subsequently embedded in paraffin for histological examination.Histology showed a benign neoplastic lesion composed of meningothelial cells with wide cytoplasm and ill-defined margins, round to ovoid nuclei with no atypia and frequent nuclear pseudoinclusions, with a focal whorl arrangement and several confluent psammoma bodies (Fig. 2a-c). No mitotic figures were observed. The meningothelial proliferation was associated with extensive areas of lamellar bone tissue, with fibrous bone marrow alternating with hematopoietic bone marrow, composed by maturing erythroid and myeloid elements and megakaryocytes (Fig. 2a-c). The periphery of the lesion was mainly composed of the meningothelial component.Immunohistochemistry showed positivity of the meningothelial cells for vimentin and EMA; p53 immunostain was negative; the Ki67 immunoreaction demonstrated an MIB-1 index less than 1% in the meningothelial line, more than 60% in the hematopoietic compartment. A myeloperoxidase immunostain highlighted the presence of a conspicuous maturing myeloid component in the hematopoietic marrow (Fig. 2d). DIAGNOSISThe histomorphological and immunohistochemical features were consistent with a diagnosis of spinal metaplastic meningioma with ossification and hematopoietic bone marrow formation.

Ossified Thoracic Spinal Meningioma with Lamellar Bone Formation presented with Paraparesis

“…From the literature, there was only one case of ossified spinal meningioma that was specifically reported to show the presence of active haematopoietic tissue in the marrow space. 11 This feature also exists in our patient.…”

Multiple ossified spinal meningiomas in the thoracic spine: A case report and literature review

“…Up to now, seven studies have mentioned the formation of hematopoietic tissue in OSM. This unexpected finding seems to confirm the mesenchymal potential of meningiomatous cells, which may undergo bone metaplasia ( 9 , 11 – 13 , 19 , 24 ).…”