Treatment of scleromyxedema with melphalan.

Scleromyxedema is an uncommon cutaneous fibromucinous disease with a monoclonal protein, which has resisted a number of therapies. Eight cases followed up for as long as 12 years have provided an opportunity to observe the effects of melphalan treatment in this disease. The fibrohistiocytic and mucinous change of the skin in scleromyxedema and often the monoclonal protein can be controlled by low-dose chemotherapy. Although melphalan does not usually produce clinical toxic effects of importance, it is a myelotoxic drug and cytopenia is common; one patient died of acute myelomonocytic leukemia after ten years of successful therapy of the scleromyxedema, thus implying that long-term therapy may be dangerous by itself. These patients require close supervision. Leukocyte and platelet counts must be performed every three weeks, and the dosage of melphalan adjusted accordingly.