術後Cisplatin-etoposide併用療法が有効であった大脳基底核部Embryonal Carcinomaの1例

Cisplatin-Etoposide Chemotherapy of an Embryonal Carcinoma Arising in the Basal Ganglia of the Cerebrum:A case report

I．はじめに

　頭蓋内原発のgerm cell tumorは，そのほとんどが松果体部や鞍上部に発生し，組織型はgerminomaが多いとされている^2,3）．今回われわれは，大脳基底核部に発生し，血中および髄液中ともにHCG（human chorionic gonadotropin）とAFP（alpha-fetoprotein）の高値を認め，組織学的にもembryonal carcinomaと診断し，術後cisplatinとetoposideの併用化学療法（PE療法）にて良好な経過が得られた症例を経験した．大脳基底核部に発生したembryonal carcinomaの報告はきわめて少なく^{1,8,13,15,16）}，また術後のPE療法についても文献的考察を加え報告する．

Cases of embryonal carcinoma arising in the basal ganglia are rarely reported. According to the literature available, only 5 cases of embryonal carcinoma, arising from the basal ganglia, have been reported to date. This paper reports one such case we recently encoun-tered. The patient was a 15-year-old boy. He was first admitted to another hospital because of occasional headache and vomiting. During the hospital stay, CT scans revealed abnormalities. For this reason, the pa-tient was referred to our critical care center. Upon admission to our center, a physical examination re-vealed no abnormalities, but neurological examination disclosed left hemiparesis. CT scans revealed a large mass lesion of a low to high density in the right basal ganglia, accompanied by midline shift and ventricular dilatation. Elevation of human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP) in both serum and cerebrospinal fluid (CSF) was observed. The tumor with multiple cysts was removed totally by cra-niotomy. The removed tissue was rated histopathologi-cally as mixed-type germ cell tumor composed of ger-minoma and embryonal carcinoma. The removed tumor cells were found immunohistologically to contain HCG and AFP. Postoperative CT scans showed complete disappearance of the tumor. Taking into account a re-cent report that a combined cisplatin and etoposide therapy (PE chemotherapy) was effective in treating intracranial germ cell tumors, we used this chemother-apy for postoperative management of this patient. The patient underwent 3 cycles of PE chemotherapy during the 3 months after surgery. The elevated HCG and AFP levels in serum and CSF returned to their normal range within 2 months after surgery. CT and tumor markers revealed no signs of recurrence. As a mainte-nance chemotherapy for this tumor, the patient was given 1 cycle of PE chemotherapy during 2 or 3 month period. At present, 12 months after the surgery, the boy attends a senior high school and visits our clinic once every month.