Shunt-related Abdominal Metastasis of Cerebral Teratocarcinoma: Report of an Unusual Case and Review of the Literature

Abstract
Internal drainage of cerebrospinal fluid to the abdominal cavity via a ventriculoperitoneal shunt (VPS) is a common procedure for therapy of obstructive hydrocephalus; because this condition is often caused by brain tumors blocking the natural cerebrospinal fluid pathways, the VPS as an artificial anastomosis can provide the means for the spreading of tumor cells by the cerebrospinal fluid. We report the case of a VPS-related abdominal metastasis of a teratocarcinoma and review the pertaining literature. A 24-year-old man with a history of three brain tumors that were operated on when the patient was 14, 21, and 23 years of age developed an acute ileus 7 months after VPS insertion for cerebral teratocarcinoma. Intraoperatively, a massive abdominal tumor was observed, which turned out to be a peritoneal metastasis of the aforesaid brain tumor. The patient died as a result of his illness 1 month later. To date, 58 VPS-related metastases of brain tumors have been described. The male-to-female ratio is 1.6:1, the mean age at shunt insertion is 12.2 years, and the interval between shunt operation and diagnosis of metastases is 16.8 months. During the observation time, 69.2% of the patients died as a result of their illness or abdominal metastases. The most common sources of the metastases were germinomas (27.7%), medulloblastomas (19.1%), and endodermal sinus tumors (10.3%). The presented case is only the second VPS-related abdominal spreading of a cerebral teratocarcinoma. Metastases via VPS are rare but should be considered as a possible complication and mode of systemic spread in patients with primary intracranial malignancy.