Spinal ossified meningiomas

Introduction. Meningiomas constitute 25% of primaryspinal tumours and predominantly involve the thoracicspinal cord. Although calcifications are commonly seenin intracranial meningiomas, gross calcifications arerare in spinal tumours and are observed in only 1% to 5% ofall spinal meningiomas. Ossification in spinal meningio-mas is even more unusual and is rarely reported.Ossified spinal meningioma is a rare variant characteri-zed by the presence of a variable number of bonespicules within the tumor itself. The pathogenesis ofossification could be consequent to metaplasia of thearachnoidal cells and/or tumor’s connectival stroma orossification of the tumor calcifications.Objectives. We report the clinical findings, surgicaladopted strategy and histological features of 9 patientswith ossified spinal meningiomas treated in our De-partment.Materials and Methods. 8 patients (89%) were womenand only 1 patient was male (11%). The mean age was59 years, ranging between 40 and 86 years. The lesionswere localized in 7 patients (78%) in the thoracic seg-ment while in 2 patients (22%) in the lower cervicalsegment. Neurological findings were related to the tu-mour localization, all patients (100%) presenting withweakness of the lower limbs and hypoaesthesia below the site level of the lesion. Only 2 patients (22%) presen-ted urinary incontinence. All patients underwent surgi-cal treatment through a laminectomy and microsurgi-cal removal of the lesion.Results and Conclusions. In 6 patients (67%) we obtai-ned the complete removal of the lesion (Simpson 2),while in 3 patients (33%) a subtotal removal of themeningioma (Simpson 3) was achieved. In all patientsthe postoperative course was uneventful. 6 patientspresented a significant improvement of both parapare-sis and hypoaesthesia, while in 3 patients (those inwhich a subtotal removal was performed) there wasonly a mild improvement of paraparesis. Histologicalexamination showed in 7 cases osseous component inassociation with psammoma bodies and dystrophiccalcifications. In 2 cases, in which no psammoma bo-dies or calcifications were found, we observed foci com-posed of immature bone trabeculae, mineralized chon-droid matrix, and osteoclasts, suggesting enchondralossification.Ossified meningiomas represent a surgical challengebecause of the difficulty to reduce the tumour volume,due to its hard-rock consistence, and remove the lesionen-block, by a fine dissection of the vascular adheren-ces, avoiding damage to the neurovascular structures.