Abdominal inflammatory myofibroblastic tumours in children.

Inflammatory myofibroblastic tumours (inflammatory pseudotumours) occurring at intra-abdominal sites in children have rarely been described. This paper reports three patients with this tumour, two of whom presented with fever, anaemia and an abdominal mass, the third with chronic duodenal obstruction. All had experienced significant weight loss. At operation, each had a large fibrous tumour (7-18 cm in diameter) originating from the transverse mesocolon, small bowel mesentery and duodenum respectively. Intraoperative frozen section histological examination in one patient was misinterpreted as a sarcoma. All the lesions were judged to have been completely excised, but one was ruptured during operation and the patient subsequently developed recurrent tumour nodules. Abdominal inflammatory myofibroblastic tumours are rare. They may be suspected before operation but their clinical, radiological and pathological features may be confused with those of malignancy. Complete excision is necessary to avoid local recurrence.