Case of Splenic Marginal Zone Lymphoma Presenting as Acquired Angioedema

Acquired angioedema (AAE-C1INH) is a rare, potentially life-threatening disorder resulting from acquired C1 esterase inhibitor deficiency, often secondary to lymphoproliferative diseases such as splenic marginal zone lymphoma (SMZL). We report on a 68-year-old woman presenting with facial and tongue swelling, gastrointestinal symptoms, and splenomegaly. Laboratory work-up revealed low C1 esterase inhibitor and C1q complement levels, consistent with AAE-C1INH. Imaging showed marked splenomegaly with increased fluorodeoxyglucose uptake; bone marrow biopsy confirmed SMZL. Treatment with rituximab and bendamustine chemotherapy led to clinical improvement, normalization of complement levels, and cessation of angioedema episodes.