Preschooler with 2 weeks of abdominal distension

Radiograph and ultrasound of CSFoma
AP and lateral radiographs of the abdomen show the VP shunt to be coiled upon itself and there is a suggestion of a retrogastric mass on the lateral view. Transverse US of the left upper quadrant of the abdomen shows a large cystic structure with the VP shunt tip within it.

The diagnosis was VP shunt malfunction due to CSFoma.