Anatomical and histological spectra of intracranial meningiomas seen in KNH; a retrospecctive and prospective study

Abstract

Introduction: Meningiomas are usually benign. slow-growing tumors. originating from the arachnoid cap cells. They account fix approximately ':2000 of all primary intracranial tumors and they arc the second commonest brain tumor. The incidence seems to be higher in Africa. at 24-38 per cent Approximately 90 % ofthe intracranial meningiomas are supratentorial The anterior half is involved far more frequently than the posterior half. The most common sites are the convexity, parasagittal, falx and sphenoid ridge. together making up 60 00 of intracranial omemngromas

Objectives: The aim of this study was to determine the clinical. radiological and histological pattern of intracranial meningiomas at KNH The specific objectives were to determine the sociodemographic characteristics and clinical presentation and correlate this to the clinical patterns ofintracranial meningiomas. to determine the intracranial anatomical locations of meningiomas and to document the WHO histoiogical grades of meningiomas operated at KNH

Material and Methods: A two years retrospective and prospective study was carried out at KNH Fifty patients managed between April 2009 and August 20 I 0 were recruited in the retrospective arm. Their medical records and imaging studies were reviewed The histology blocks were retrieved and examined In the prospective ann a total of 28 patients with clinical and radiological findings suggestive of meningioma were recruited between September 2010 and April 201 I Histological examination of their biopsy was also done

Results: A total of 78 patients managed at KNH for intracranial meningiomas were sampled and included in the study Females (692°'0) were more affected than males (308%) Meningiomas occurred in supratentorial compartment (8S9~o) more frequently than infratentorial compartment (141 °0) Anterior cranial base was the commonest location comprising of 51 5~'o (Tubercullurn sellar S 9%. olfactory groove 20.6°0 and Sphenoid wing 25%) Commonest location of meningiomas in the posterior fossa was the tentorium 60°'0 and the petrous region According to WHO classification. the benign form (grade I) was the commonest at 94.7% Grade II (atypical) and grade III (malignant) represented 4°0 and 13°0 respectively The commonest cellular subtype in grade I tumours were fibroblastic 254°'0. transitional (mixed) 254% and meningothelial (svncitial ) at 22.500

Conclusion: Meningiomas occurred more frequently in females than in males with a female to male ratio of2! Young adults were more affected than their elderly counterparts The mean age was 426 Patients presented late with majority having large tumours and significant visual impairment.There is significant decline in operative mortalitv reflecting improvement in neurosurgical care.Most intracranial meningiomas occur in the supratentorial compartment with anterior cranial base contributing over tift) percent. 'majority of meningioma are histologically benign and hence curable by' surgical resection