Acquired C1 inhibitor deficiency with lymphoma causing recurrent angioedema

A 52 year old man who developed recurrent, massive and generalized angioedema for the first time during adult life was found to have an acquired deficiency of C1q esterase inhibitor (C1 INH) in association with a B cell lymphoma producing a paraprotein. He had low levels of C4 and C1 INH during the attacks which returned to normal after the successful treatment of lymphoma. An underlying lymphoproliferative disease should always be considered in adult patients with this immunological profile, recurrent angioedema and a negative family history.