Abstract: Multiple myeloma is a malignant proliferation disease of plasma cells, which produces a large number of monoclonal immunoglobulin or fragments, resulting in osteolytic lesions, anemia, hypercalcemia, renal dysfunction and other clinical manifestations. Secondary amyloidosis is rare. We report a case of multiple myeloma complicated by amyloidosis with cutaneous nodules as the initial manifestation. A 60-year-old female presented with cutaneous nodules all over the body for 1 year. Bone marrow biopsy showed that the proportion of plasma cells increased to 10%, of which immature plasma accounted for 6%. Serum protein electrophoresis revealed M protein bands. Immunohistochemistry showed CD38(+), CD138(+). Pathology showed amyloid deposits accompanied by granulomatous reaction, with positive Congo red staining. The patient was transferred to the department of hematology for chemotherapy after diagnosis, and the skin lesions subsided during the follow-up.

Key words: multiple myeloma, cutaneous nodules, amyloidosis