Angioedema with normal C1q and C1 inhibitor: An atypical presentation of Waldenström macroglobulinemia

Angioedema is a recurrent, non-pitting, non-pruritic, transitory swelling due to transient increase of endothelial permeability in the capillaries of the deep cutaneous and mucosal layers. Angioedema is generally categorized based on etiology, and characteristic lab findings are associated with each category. Cases of acquired angioedema associated with myeloproliferative disorders have been described in the literature, but these have been associated with a characteristic low C1q, a defining laboratory finding in acquired angioedema. Here we present a case of 68-year-old female with acquired angioedema that was not associated with low C1q, but was found to have Waldenström disease. Her angioedema responded dramatically to combination therapy consisting of bortezomib, rituximab, and dexamethasone.