Atypical and Malignant Meningiomas

Abstract

There has been continuing debate on the subject of malignant meningiomas, but few studies of large series have been reported. We present our experiences with 25 atypical and malignant meningiomas operated on at Henry Ford Hospital between 1976 and 1990. A total of 319 primary intracranial meningiomas were operated on during this period; of these, 294 (92%) were benign, 20 (6.26%) atypical, and 5 (1.7%) malignant. We used a modified histological grading system, based primarily on World Health Organization criteria of malignancy (hypercellularity, loss of architecture, nuclear pleomorphism, mitotic index, tumor necrosis, and brain invasion), to define atypical and malignant meningiomas. Each of these criteria was given a score from 0 to 3, and then partial scores were added to obtain cumulative scores. These total scores were then used to determine what is benign, atypical, and malignant. The peak incidence of atypical and malignant meningiomas was in the seventh and sixth decades, respectively. The predominance of female patients with benign meningiomas was not observed in the nonbenign group. The male:female ratio for atypical and malignant meningiomas was 1:0.9 versus 1:2.3 for benign meningiomas (P = 0.024). The most common presenting symptom and physical sign in our patients was paresis. In reviewing their radiographic features, all patients showed moderate or marked edema on computed tomography. Calcification was exhibited by one patient only and "mushrooming" was seen in three cases. Of the 25 patients, 11 (44%) died during follow-up: 2 in the perioperative period, 8 within the first 5 years, and 1 died 11 years after the diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Atypical and anaplastic meningiomas in a public hospital in São Paulo State, Brazil

“…We found 8.2% of patients with grade II and 1.7% with grade III (10% of the patients with meningiomas surgically treated), data similar to the recent series. Benign meningiomas predominates in patients of female sex; in contrast, gender distribution has been reported similar or even with male predominance among patients with Grades II/III 2,8,12,13,14,15 . Our results kept this tendency for patients with grade II and III tumor.…”

“…The wide range in the relative frequency of atypical (3.6 and 7.5%) and anaplastic meningiomas (0.4 to 2.8%) 1,2,3,5,8,9,10,11 , can be explained by variable pathological criteria for their classification. However, the use of the WHO criteria improved comparisons among more recent series.…”

“…Several histopathological classifications were proposed for more aggressive meningiomas 2,18 , however, these classifications are potentially subjective. Perry et al 19,20 , elaborated a simple and reproducible grading scheme for meningiomas (The Mayo Clinic Scheme), based primarily on histological features in patients who underwent total resection.…”

Epidemiology of Meningioma in the United Kingdom

“…Approximately three-quarters of meningiomas are asymptomatic [3]; symptoms, when they do occur, commonly include seizures, headaches, hemiparesis, changes in mental health and visual impairments [4,5]. Approximately 92% of meningiomas are benign (WHO grade 1), 6% atypical (WHO grade II) and 2% malignant (WHO grade III) [6,7]. In a recent study, the overall 5-year survival rate was 78% for atypical meningiomas and 44% for malignant tumors [8].…”

A rare intracranial tumor of Psammomatous anaplastic meningioma

“…[1] The peak incidence of atypical and malignant meningioma was in the seventh and sixth decades, respectively. [7] These anplastic meningioma are defined by several criteria including: 1) Invasion of adjacent brain parenchyma or skull, 2) Numerous mitoses (> 5/highpowered field), 3) Elevated proliferative index (>3%) as assessed by either 5bromodeoxyuridine or KI-67 staining, 4) Necrosis, 5) Increased cellularity, 6) Nuclear pleomorphism and 7) Metastasis. [1,5,[8][9][10][11][12] The cell origin of the meningioma's is the arachnoid cap cell, which has a slow rate of cell division.…”