Cytogenetic studies of human brain tumors and their clinical significance. 1. Medulloblastoma.

Four medulloblastomas were studied cytogenetically with clinical follow-up of the patients. Three of these lesions were diploid and the patients manifested no recurrence at 40, 37 and 36 months respectively. The remaining tumor was aneuploid with 52 chromosomes and the patient expired of the medulloblastoma in 7 months. These findings are compared to nine previously reported karyotypes of primary medulloblastomas only two of which had clinical follow-up of the patients. On the basis of our results and these previously reported cases it appears that medulloblastomas with a diploid chromosomal pattern have a better prognosis than those with aneuploidy.