The incidence of central nervous system (CNS) lesions in Malaysia: A histopathological study of 1064 cases from the year 1991 till 1994

Abstract

A study on the incidence of the CNS lesions over a period of 4 years was conducted in two major hospitals in Malaysia. Once is a University Hospital (HUSM) located at the northeastern part of west Malaysia (referral centre for northeastern region), while the other is Neurology Institute (NI) a general hospital located at the central region and is a national neurological referral centre. During the period, a total of 1064 (histologically verified) consecutive lesions were seen involving the brain and the spinal cord. Of these, 872 (82.0%) cases were neoplasms of which 293 (33.6%) were malignant. 108 (10.2%) cases were inflammatory, 69 (6.5%) were congenital and the rest was of miscellaneous in nature. In descending order, out of 872 neoplastic cases tumours of the neuroglial origin were 203 (23.3%), of meningothelial origin 193 (22.1%), nerves and nerve sheaths origin 90 (10.3%), vascular origin 70 (8.0%), primitive and undifferentiated cells 68 (7.8%), pituitary adenomas 66 (7.9%), metastatic tumours 57 (6.5%), malformative tumours 54 (6.2%), germ cell tumours 12 (1.4%), non Hodgkin lymphomas 11 (1.3%) and neuronal tumours were 5 (0.6%). The miscellaneous tumours were 43 (4.9%) cases. Of the 108 inflammatory lesion, 55 (50.9%) were due to pyogenic abscesses, 16 (14.8%) were due to Tuberculosis, 10 (9.3%) due to crytoccoccosis while the microorganisms were not detected or identified in the rest of the inflammatory lesions. Of the 64 congenital lesions, meningoencephaloceles formed the majority, 85.9% (55 cases). Malaysian comprise of three major ethnic groups, the Malays, the Indians and the Chinese. Of interest to note that in all the five main primary brain tumours; meningiomas, astrocytomas, schwannommas, pituitary adenomas and medulloblastomas, the incidence among the ethnic Malays in the highest, 54.7% (293/536), followed by the Chinese, 27.6% (148/532) and lest among the Indians, 11.7%. The incidence of all CNS lesions per 100,000 population was 1.5, while the incidence of malignant neoplasms of CNS was 0.5. These figures are compared with the incidence of CNS lesions in other countries.