Introduction: The purpose of the study is the evaluation of the outcome of the operatively treated meningiomas in relation with the Karnofsky performance score, survival, recurrence, type of the surgical excision, histological type, mitotic count (MC), localisation and volume of the lesion

Methods: Group of 40 randomly selected patients with supra and infratentorial meningiomas treated at the Univ. Clinic for Neurosurgery – Skopje, during the period between 2006 and 2011 has been analysed. The subject of the analysis are operated patients, with a tendency to achieve "gross total resection" (Simpson Grades I and II), as well as patients undergoing "subtotal resection", (Simpson Grade III, IV and V).

Results: 40 enrolled patients: 13 (32.5%) were male, 27 (67.5%) were female. Mean age: 58.58 ± 8.91 years of age, with minimal age of 42 and maximal age of 78. Average lesion volume: 40.23 ± 16.39ccm, with minimal volume of 7ccm and maximal volume of 80.00ccm. Histological type: 32 patients (80%) had a typical meningioma, 7 patients (17.5%) had an atypical meningioma and one patient (2.5%) had anaplastic meningioma. Localisation: 18 patients (45%) with meningioma localised on the cranial base, 12 patients (30%) with meningioma localised on falx-tentorium, 10 patients (25%) with convexity meningioma. Mitotic count: 34 patients (85%) had a Grade I, 4 patients (10%) had a Grade II and 2 patients (5%) had a Grade III mitotic count. Karnofsky Performance Scale: 32 patients (80%) had a score of 80% or higher, 7 patients (17.5%) had a score from 50-80% and 1 patient (2.5%) had a score of 50% or lower. Simpson scale: 24 patients (60%) had a Simpson I resection, 12 patients (30%) had a Simpson II resection, and 4 patients (10%) had Simpson III resection. In 29 patients (72.5%) no tumour regrowth was noted after the first operation and in 11 patient (27.5%) tumour regrowth was diagnosed.

Conclusions: Degree of surgical resection is associated with tumour regrowth. The mitotic count in different types of meningiomas is significant feature in tumour regrowth. There is no connection between the size and the localisation of the tumour related to different values of the mitotic count.

Patient Care: Emphasising the importance of maximal surgical resection during the first operation, using micro-surgical resection techniques which maximises the chances for cure

Learning Objectives: By the conclusion of this session, participants should be able to see the importance of maximum surgical resection in relation of other prognostic factors such as mitotic count, patient age, localisation and outcome estimated according to Karnofsky performance status and also tumour regrowth.

References: 1. Simpson D: The recurrence of intracranial meningiomas after surgical treatment. J. Neurol. Neurosurg. Psychiat. , 1957,20,22. 2. The mitotic count in different types of meningiomas presents significant feature in the appearance of meningioma recurrence 3. Perry A, Stafford SL, Scheithauer BW, et al. Meningioma grading: an analysis of histological parameters. Am J Surgical Pathology 1997;21:1455-1466 4. Perry A, Stafford SL, Scheithauer BW, et al. The prognostic significance of MIB-1, p53, and DNA flow cytometry in completely resected primary meningiomas. Cancer. 1998;82:2262-2269 5. Kim JY, Ralf Ketter, Wolf-Ingo Steudel, Wolfgang Feiden: Prognostic significance of the mitotic index using the mitosis marker anti-phosphohistone H3 in Meningiomas; 6. Mahmood A, Caccamo D V, Tomecek F J, et al.: Atypical and Malignant Meningiomas: A Clinico-pathological Review. Neurosurgery 33: 955-63, 1993