[A case report of a 6-year-old boy with intracranial yolk sac tumor treated by VAB-6 regimen].

Several clinical trials have demonstrated that cisplatin-based chemotherapy for primary intracranial germ-cell tumors is effective as a neoadjuvant chemotherapy. In this report, we describe a 6-year-old boy, Down syndrome and Hirschsprung's disease with intracranial pure yolk sac tumor treated by combined chemotherapy with cisplatin, vinblastine, bleomycin and cyclophosphamide (modified VAB-6 regimen). He had been admitted to our hospital because of intractable vomiting, and left facial nerve palsy since 1 month before. An MRI revealed an enlarged mass, 4cm in diameter, in the left cerebello-pontine angle with uniformal enhancement by Gd-DTPA, and bilateral ventricular dilatation. He was found to have increased serum alpha-fetoprotein level (AFP 11, 786ng/ml), but not human chorionic gonadotropin beta-subunit. After a partial resection of the tumor, diagnosed as pure yolk sac tumor, and ventriculo-peritoneal shunt, three courses of combined chemotherapy with cisplatin, bleomycin, vinblastine and cyclophosphamide (modified VAB-6 therapy) were carried out. The serum AFP level returned to normal, and the tumor mass entirely disappeared (a complete response) on MRI after the second course of chemotherapy. However, cisplatin-induced vomiting and mild neutropenia and renal tubular injury developed after the third course of chemotherapy. Irrespective of administration of recombinant human G-CSF and broad spectrum antibiotics, he suffered from pneumonia and died of septic shock and multiple organ failure. Autopsy showed microscopic residual tumors. The combination chemotherapy with cisplatin, bleomycin, vinblastine and cyclophosphamide is effective for initial treatment of childhood intracranial yolk sac tumor. It is necessary, however, to reevaluate the cisplatin dosage and treatment schedule in order to reduce such side effects as bone marrow suppression and renal damage.