Cutaneous infiltration with Waldenström macroglobulinemia

A 59-year-old Japanese man was diagnosed as Waldenström macroglobulinema. With impaired general performance and a 2-year history of pruritic eruptions that were initially confined to the forearms, but later involved the face, limbs, and trunk. A skin biopsy that was performed on the forehead showed infiltration with abnormal cells of the dermis around the central vessels. PCR analysis of the skin biopsy showed immunoglobulin heavy chain rearrangement. As the rearrangement band occurred at the same site as that of the bone marrow aspiration, skin infiltration with abnormal cells was proven.