An abdominal mass in a 4-year-old child.

The author describes a 4-year-old boy who presented to the accident and emergency department after a mass in his abdominal wall had been rapidly enlarging for at least a week. There was a delay in management due to difficulty reaching the diagnosis. Once obtained, a CT scan revealed the true diagnosis; an infected intramuscular haematoma arising from the right abdominal oblique muscles. This was large enough to displace the right lobe of the liver medially. The patient was treated with surgical drainage and intravenous antibiotics.