Recurrent pseudocyst from a ventriculoperitoneal shunt. An unusual abdominal mass.

A 4-year-old girl developed a recurrent abdominal pseudocyst from a ventriculoperitoneal shunt. There was no infection of the peritoneum or CSF. Diagnosis of this unusual abdominal mass was made roentgenographically by direct injection of soluble contrast material under antiseptic conditions into the shunt tubing. Ultrasonography was confirmatory. Management included excision of the cyst and removal of the shunt catheter from the peritoneal cavity.