Clinicopathologic analysis of 615 cases of meningioma with special reference to recurrence.

A total of 615 cases of meningioma operated on from 1959 to 1992 at National Taiwan University Hospital were reviewed. Factors influencing tumor recurrence were also evaluated. Of the 566 patients with intracranial meningioma, 350 were females and 216 were males (F:M = 1.6:1). The mean age was 47.5 years. The distribution of histologic type was: 232 meningothelial (41%), 141 transitional (24.9%), 106 fibroblastic (18.7%), 42 atypical (7.4%), 16 anaplastic (2.8%), and 29 angioblastic [5.2%, including five hemangioblastic (0.9%) and 24 hemangiopericytic (4.3%)]. Anatomical locations were parasagittal/falx area (35%), cerebral convexity (19.3%), sphenoid wing (10.2%), posterior fossa (7.4%), tuberculum sellae (6.7%), olfactory groove (5.7%), tentorium (4.8%), middle fossa (3.7%), and others (7.4%). Recurrence occurred in 83 patients, with a total 19.4% recurrence rate at five years. Sex, histologic grade, and tumor location were associated with recurrence. The recurrence rate was 19% for males and 12% for females (p < 0.05); while it was 42.9%, 64.3%, and 69.6%, respectively for atypical, anaplastic and hemangiopericytic meningiomas, which was much higher than 12.2% for benign ones (p < 0.005). Tumors in less accessible surgical sites also had a higher recurrence rate (p < 0.005). There was no correlation between the age of patients, the tumor size, and the histological subtypes and variants. Of the 49 spinal meningiomas, the majority occurred in adult females (80%), were benign in nature (98%) and thoracic in location (71.4%).