ASTROCYTOMA AND PINEALOBLASTOMA ARISING SEQUENTIALLY IN THE 4TH-VENTRICLE OF THE SAME PATIENT - CASE-REPORT AND MOLECULAR ANALYSIS

The sequential appearance of two different brain tumors in the same pa tient without intervening radiation or chemotherapy is a rare event, m ost often seen in hereditary cancer syndromes. We present one such cas e of sequential tumors, along with their molecular analysis. A 17-year -old male presented with a pilocytic astrocytoma arising in the fourth ventricle at the pontomedullary junction. Six and one half years late r, a pineoblastoma was discovered in the fourth ventricle, rostral to the first tumor site. Both tumors were treated by gross-total surgical resection. Following resection of the pineoblastoma, the patient unde rwent craniospinal irradiation and systemic chemotherapy. Single-stran d conformation polymorphism analysis showed that the patient had neith er a germ-line mutation nor a somatic tumor mutation in the p53 tumor suppressor gene. Coupled with the lack of a family history of cancer, these data suggest that these were not manifestations of Li-Fraumeni s yndrome, but rather two sporadic tumors which arose via a p53-independ ent mechanism.