Perivascular hemosiderin deposition in muscle in Waldenström's macroglobulinemia

A 63-year old woman with Waldenström's macroglobulinemina of 5 years' duration developed disabling pain in her extremities. The patient had required frequent plasmapheresis and transfusion for treatment of hypervisosity. Muscle biopsy from 2 separate sites showed striking deposition of hemosiderin in macrophages surrounding small vessels and features of slight denervation. Immunofluorescence demonstrated IgM deposition in vessel walls. Perivascular hemosiderin deposition in muscle has not previously been desicribed and may reflect traansfusion-hemosiderosis in a patient with a dysglobulinemia.