| dc.description.abstract | Background: Meningiomas are the second most common central nervous system tumors,
accounting for 15- 46% of primary brain neoplasms. Although often considered benign, about 20% of meningiomas display aggressive histological and clinical features accounting for significant patient morbidity and mortality. Studies have shown that these neoplasms are more common and more aggressive in non white populations but the histological patterns of these neoplasms in KNH have not been documented. Immunohistochemistry used as an adjunct to meningioma diagnosis is standard tool for diagnosis of these neoplasms elsewhere but is not routinely used in KNH. Rare meningioma subtypes have been documented elsewhere but none in KNH. ** Objectives: The objective was to describe the histological subtypes of symptomatic meningiomas that were encountered in KNH in the period 2002 to 2005. A second objective was to evaluate the value of IHC in diagnosis of meningioma. ** Design: A retrospective and prospective descriptive study of 150 meningioma cases operated on during the period January 2002 to Dec 2005. ** Setting. Kenyatta National Hospital Department of Human Pathology laboratory. KNH is Kenya's main Referral and Teaching Hospital. ** Subjects: 96 meningioma cases operated during the period 2002 to December 2004 and 54 patients operated for and diagnosed with meningioma during the period 2005 making a total of 150 meningioma cases. ** Methods: Clinical data and histological reports of cases of meningioma operated on in the period January 2002 to December 2004 were analyzed. Patients diagnosed with meningioma during the study period (year 2005) were included. A questionnaire was used to collect the data. Histological sections were studied using routine HIE sections. Five of the common immunohistochemical markers, vimentin, EMA, S-100, glial fibrillary protein and Neurone specific enolase were used. ** Main outcomes: Meningiomas are proportionately more common in KNH accounting for 38% of intracranial tumours comparable to other studies in non white populations. Aggressive meningioma variants (grade 11&111) were 19.9% of the cases. Meningothelial and Transitional meningiomas are the commonest benign variants accounting for 35% and 30% respectively. Over all 13.3% of meningiomas required IHC for confirmation of diagnosis. Most of the retrospective cases reviewed did not have relevant clinical data. Presence of history did not significantly alter the need for IHC. There is still significant interobserver variation in reporting of meningiomas. ** Conclusions: Meningothelial and Transitional meningiomas are the commonest benign variants accounting for 35% and 30% respectively and meningiomas remain the second most common intracranial tumours in KNH. Grade II and Grade III meningiomas accounted for 19.9%; comparable to those of other non white population studies. Immunohistochemistry is needed in 13.3% of cases for complete description of meningiomas subtypes. Despite the utilization of WHO guidelines, there still remains a significant interobserver variation. Documentation of clinical history and histological subtypes of meningioma is not complete. ** Recommendations: A basic immunohistochemistry panel comprising of epithelial marker (EMA) and Vimentin, would be of value for diagnosis of meningioma however the extra cost of Ksh 2000 is prohibitive for routine. In view of the higher proportion of high grade meningiomas 19.9% (grade II 15.9% and III 4%) and the apparent rise in numbers of meningiomas 28 (2002), 33 (2003) 35 (2004) and 54 in 2005, a comprehensive audit with all the items: clinical presentation, signs, accuracy of cranial imaging, presurgical work up, surgical complications, delays in the process of service, recurrence rates and complications of treatment should be done. An audit would shed more light on the adequacy management of these patients and would encompass clinical and laboratory management. A standard Neurosurgical histology request form should be developed which covers the unique requirements in clinical history, radiology and intraoperative data. | en_US |
