Abdominal cerebrospinal fluid pseudocyst: a complication of ventriculoperitoneal shunts in adults.

Abdominal cerebrospinal fluid pseudocyst is an uncommon complication of using ventriculoperitoneal shunt (VPS). Although many cases have been reported in children, abdominal pseudocysts are rare in adult patients. The purpose of this article is to describe and illustrate the findings for this condition on commonly used abdominal diagnostic imaging modalities. This is a retrospective review of the six adult patients diagnosed with abdominal pseudocyst as a consequence of VPS at our centre from 1995 to 2006. We reviewed patients' prior history, cerebral and abdominal clinical manifestations, imaging findings, treatment and evolution. All patients presented with pain and abdominal distension associated with the presence of a palpable mass. Plain-film radiography was carried out in one patient, ultrasound in three and CT in all six. A fluid collection close to or associated to the VPS catheter was observed in all cases. Visualization of the distal tip of the VPS within a homogeneous intraperitoneal collection is the principal diagnostic sign of an abdominal cerebrospinal fluid pseudocyst at ultrasound and CT.