Acquired C1-esterase inhibitor deficiency: three case reports and commentary on the syndrome.

Acquired C1-esterase inhibitor deficiency is a rare syndrome which usually presents with episodes of angioedema. Most patients have an underlying lymphoproliferative disorder. It is important to gastroenterologists, haematologists, immunologists and dermatologists, as these are the more likely specialties to which the patient will present. Recognition of the syndrome is important not only for diagnostic purposes but for investigating and treating any associated underlying lymphoproliferative disorders. In some instances the angioedema may precede the lymphoma by many years. Optimal patient management requires that both angioedema and the underlying lymphoma be recognized and treated.