GCT-47. TREATMENT STRATEGIES FOR GIANT IMMATURE TERATOMAS IN INFANTS

INTRODUCTION: Immature teratomas are the most frequent fetal brain tumors and show a poor prognosis. At onset, the tumor is often already giant with deep origins such as suprasellar or pineal region, and easy bleeding is also considered to be a cause of poor prognosis. On the other hand, it is also known that the prognosis is improved in total removal cases. METHODS: We investigated the best treatment strategy based on two cases of total removal of giant immature teratomas in infants. RESULTS: 1.5 month after birth at onset (median), maximum diameter of 75 mm (median). A giant tumor centered around the third ventricle with hydrocephalus. First, biopsy (+septostomy) was performed using an endoscope. The tumor showed easily bleeding. In addition, external ventricular drainage was taken out of the lower abdomen subcutaneously by long tract. After chemotherapy (carboplatin and etoposide), tumor removal was performed by using drainage tract. Both cases showed not easily bleeding at that time and the tumor was safely removed. Regarding the deep blind spot, using a flexible endoscope was effective. They showed no recurrence after total removal (median 50 months). DISCUSSION: There have been reports of cases in which chemotherapy for immature teratomas suppressed tumor growth and reduced bleeding and safely removed totally. In infants giant immature teratomas, chemotherapy before tumor removal can be expected to reduce bleeding, and further increase body weight during that period. In addition, long-term placement of ventricular drainage by long tract during the chemotherapy can prevent brain development delay due to hydrocephalus.