A Case of Dialysis-Related Amyloidosis Presenting as Large Subcutaneous Masses on the Buttocks

Abstract

We report a case of dialysis-related amyloidosis presenting as large subcutaneous masses on the buttocks. A 53-year-old man had been on maintenance hemodialysis for 33 years due to chronic renal failure and had suffered partial paralysis due to human T-lymphotropic virus (HTLV)-1-associated myelopathy. During the next few decades, he recognized that sharplymarginated, hard masses had gradually protruded on his both buttocks. Histopathological examination of the indurated area showed massive eosinophilic amorphous deposits in subcutaneous tissue, which stained with Congo red. Immunohistochemistry showed positive staining with an antibody to β2-microgrobulin (β2M). Skin lesions have rarely been reported previously in β2M-associated amyloidosis and there have been many fewer literature reports of the mass-forming type.