Abstract
Acquired von Willebrand syndrome (AVWS) is a bleeding disorder in which an underlying condition induces a quantitative or qualitative deficiency in the von Willebrand factor. This case demonstrates the rare diagnosis of AVWS due to an Immunoglobulin G monoclonal gammopathy in an elderly woman who presented with significant gastrointestinal bleeding. Originally thought to be type 1 von Willebrand disease, this case provides a cautious example to clinicians that without a detailed history or an understanding of the associated laboratory work-up, AVWS may be missed with potentially fatal consequences. Fortunately, AVWS was recognized and treated with intravenous immunoglobulin with a resolution of bleeding.