A person present with recurrent swelling on face and lips due to emotional stress.likely cause is

Ref Robbins 9/e 238; 8/e p 235 Acquired angioedema due to deficiency of C1 esterase inhibitor, also called acquired angioedema and abbreted C1INH-AAE, is a rare syndrome of recurrent episodes of angioedema, without uicaria, which is associated with B cell lymphoproliferative disorders in some patients