Intracranial hemangiopericytoma

Objectives. Describe and discuss imaging features of meningeal hemangiopericytomas (CT scan, MRI, brain angiography) as well as its preoperative treatment (embolization), its principal differential diagnoses and factors of poor prognosis. Material and methods. We reviewed the CT scan and MRI (T1WI before and after gadolinium injection, T2WI, proton density and angio-MR) for three patients. Brain angiography was available for two patients. Results. The patients were aged 37 to 60 years, and were essentially admitted for intracranial hypertension. Tumor features were well studied; locations were respectively frontal, interhemispheric and pontocerebellar. Treatment was surgical, and histological examination revealed meningeal hemangiopericytomas. Discussion. Meningeal hemangiopericylomas are rare hypervascular tumors, accounting for less than 1% of intracranial tumours. Certain CT scan and MRI signs are suggestive of this extra-axial tumor: "mirror" tumor growth pattern, absence of calcifications, absence of surrounded edema, wide dural attachment and absence of osteosclerosis adjacent to its insertion. If these signs are not present, the aspect lacks specificity, and can lead to confusion with meningioma. Brain angiography often provides supplementary arguments for diagnosis, and allows a preoperative embolization of this hypervascular tumor. Conclusion. Imaging diagnosis of meningeal hemangiopericytoma is not always straightforward, because it resembles classical meningioma. Histological proof is necessary. Certain factors of poor prognosis are recognized: tumor location and size, histological grade, postoperative radiotherapy, and presence of metastasis. (C) 2010 Elsevier Masson SAS. All rights reserved.