[Abdominal metastasis of a pineal region tumor through ventriculoperitoneal shunt. Case report].

An 18-year-old male was admitted with headache, nausea, and vomiting. Computed tomography (CT) revealed an enhanced tumor of the pineal region and hydrocephalus. The tumor was partially resected via a parieto-occipital craniectomy. The histological diagnosis was germinoma. No serum tumor markers such as alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were detectable. A ventriculo-peritoneal (V-P) shunt was emplaced and radiation therapy (whole brain 59 Gy) given. The tumor and the hydrocephalus regressed completely and he returned to work. Six years later, he experienced constipation and general fatigue. CT and echotomography of the abdomen showed a large peritoneal tumor and ascites. Laboratory investigation demonstrated serum levels of AFP 7640 ng/ml and HCG 150 IU/l, and high ascitic levels of AFP 12,890 ng/ml and HCG 1030 IU/l. AFP and HCG levels regressed after combined chemotherapy. However, he died due to leukopenia and pneumonia. Autopsy found no metastasis of tumor cells to the central nervous system. The peritoneal cavity contained hemorrhagic fluid and a large tumor 4100 g in weight. The tip of the V-P shunt tube was in front of the tumor. No neoplasm was found in the testis, retroperitoneal cavity, thymus, and other organs. The microscopic appearance of the peritoneal tumor was different to the first pineal tumor. The neoplasm was confirmed as a mixed germ cell tumor with teratoma components and suspected to be a metastasis of the pineal tumor through the V-P shunt system.