Abstract: The skin manifestations of monoclonal(M)-proteinemia are rare and present in patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering plasma cell myeloma (SMM) and multiple myeloma (MM). In this study, we reported 4 cases with M-proteinemia-related rare skin lesions, including pyoderma gangrenosum (PG), erythema elevatum diutinum (EED), cutis laxa (CL) and lichen myxedematosus(LM). These skin lesions are specific, where the potential mechanism was immune-mediated paraneoplastic syndrome rather than direct plasma cell infiltration. Anti-plasma cell treatment was effective in treating skin lesions. The clinical outcome of MM-related skin changes was correlated to tumor control, whereas the prognosis of MGUS or SMM related skin lesions was favorable. Skin involvement in M-proteinemia is extremely rare and less well-known, which greatly impairs quality of life. The diagnosis and treatment of these 4 cases support the need for futher study.