Vanishing tumour of the colon ascendens due to acquired type II C1-inhibitor deficiency.

We present a patient with recurrent bouts of angioedema of the lips, throat and extremities with a negative familial history for angioedema. Laboratory results confirmed an angioedema due to acquired C1-INH deficiency (or acquired angioedema, AAE). As AAE can result from underlying disease, further investigation toward malignancy was initiated. A CT-scan of the abdomen disclosed a circumferential tumour of the proximal segment of the colon ascendens which disappeared by the time an ileocolonoscopy was executed. Angioedema of the bowel has been widely reported in hereditary angioedema, whereas it is anecdotal in AAE.