Abstract
C1-inhibitor deficiency is a rare disease which incorporates acute self-limiting intermittent swelling of the subcutaneous tissue and mucous membranes. Attacks most frequently affect the face and/or the upper airway. Isolated angioedema of the small bowel is an uncommon manifestation and often accompanied by diagnostic delay. In the present case, abdominal pain turned out to be the first and only utterance of an acquired C1-inhibitor deficiency, secondary to a splenic marginal zone lymphoma. Imaging showed wall thickening of the small intestine, ascites and splenomegaly. The abdominal pain and intestinal wall thickening with surrounding ascites on imaging spontaneously resolved each episode within 2–3 days. Gastrointestinal manifestations of angioedema may mimic an acute abdomen, and subsequently one-third of these patients undergo unnecessary surgery prior to a definite diagnosis. This emphasises the importance of considering the diagnosis in case of an ‘extraordinary colic’.