Inflammatory tumour of the retroperitoneum--a case report.

INTRODUCTION: Neoplastic growths of myofibroblasts occurring on a background of plasma cell and lymphocytic proliferation have been designated as inflammatory myofibroblastic tumours (IMTs). These unusual tumours were first described in pulmonary location in adults. Though extrapulmonary masses have been reported in children; retroperitoneal growths are exceedingly rare. We report a case of retroperitoneal IMT that presented with constitutional symptoms without any palpable abdominal mass.

CLINICAL PICTURE: A previously well 12-year-old boy presented with fever, right-sided flank pain and weight loss of 1-month duration. There were no foci of infection. The erythrocyte sedimentation rate (ESR) was raised; the white cell count was normal. An abdominal computed tomography (CT) scan revealed a right suprarenal tumour measuring 3.5 cm without any calcification. The urinary catecholamines and vanilmandelic acid were normal.

TREATMENT: A laparotomy with complete excision of the tumour was performed. Final histology revealed an inflammatory myofibroblastic tumour without any correlates of aggressive behaviour.

OUTCOME: Postoperatively, the constitutional symptoms of fever, weight loss and raised ESR normalised. Follow-up CT was normal and further treatment was not necessary.

CONCLUSION: Although rare, IMTs should be considered in any abdominal solid tumour with associated constitutional and laboratory features of an inflammatory response. Complete surgical excision is effective treatment for biologically benign tumours.