Epidemiology of primary intracranial neoplasms in Manitoba, Canada.

The incidence of primary intracranial tumors in Manitoba, Canada was reviewed. From 1980 through 1985, 657 tumors were diagnosed. The crude incidence rates were 10.2/100,000 for males and 10.8/100,000 for females. The three most common tumors were: astrocytoma 281 (43%), meningioma 145 (22%), and pituitary adenoma 111 (17%). Average annual incidence rates for all tumors showed a bimodal distribution with one peak in the 0-4 age group (4.2/100,000), and the other in the 60-69 age group (27.2/100,000). For malignant astrocytoma, the age-specific annual incidence rate increased to the seventh decade where it reached a peak of 14.3/100,000. The incidence of benign astrocytoma remained relatively constant with age at 1.1/100,000. The annual incidence of meningioma increased with age up to the eighth decade reaching 7.2/100,000. Of the 145 meningiomas, 56 (39%) were meningotheliomatous, 48 (33%) transitional, 10 (7%) malignant, 7 (5%) fibroblastic, 6 (4%) psammomatous, 3 (2%) angioblastic, and 15 (10%) lacked pathologic diagnosis. The annual incidence of pituitary adenoma showed two peaks, the first occurring in the third decade (2.6/100,000) and the second in the eighth decade (3.2/100,000). Although the incidence of meningioma was relatively high, the clinical features and pathologic patterns of these tumors were not unlike those previously reported in the literature.