[Lichen myxedematosus and multiple myeloma type IgG/kappa].

Lichen myxedematosus and scleromyxedema are rare disorders with cutaneous deposition of mucin, without any disturbance of the thyroid function. They are regularly associated with the presence of abnormal proteins in the serum. These proteins have been now identified as paraproteins and are one of the main symptoms of these diseases. The association of a papular mucinosis with a classical plasmacytoma is exceptional. We report a patient in whom lichen myxedematosus is associated with a multiple myeloma of the type IgG/kappa. Cultured skin fibroblasts show a marked decrease of arylsulfatase A activity. An antineoplastic-steroid therapy has brought a remission of both plasmacytoma and skin lesions.