Atypical cutaneous presentation of Waldenström macroglobulinemia: An extensive erythematous patch mimicking an angiosarcoma

Waldenström macroglobulinemia (WM) is an immunoglobulin M-producing lymphoproliferative disorder in elderly individuals. Cutaneous manifestations of WM are rare and typically consist of plaques or nodules. We describe a case of a man with WM who presented with an extensive erythematous patch on the scalp that clinically mimicked an angiosarcoma.