Case report : Acquired C1 inhibitor deficiency preceding the diagnosis of lymphoma

A 62 year old lady presented with recurrent abdominal pain and angioedema due to acquired C1-inhibitor deficiency (AAE) associated with an atypical splenic marginal zone lymphoma. An attenuated androgen, stanozolol, and splenectomy resulted in prevention of attacks, and temporary normalisation of C1-inhibitor (C1-INH) antigenic and functional assays. The immunological mechanisms underlying AAE are discussed.