Scleromyxedema: long-term follow-up after high-dose melphalan with autologous stem cell transplantation

Background: Scleromyxedema is a cutaneous mucinosis that is often accompanied by severe systemic manifestations. New therapeutic options have been introduced for this condition, but data on the long-term efficacy of treatments are limited. Objectives: This study was designed to evaluate the long-term efficacy and safety of treatment with high-dose melphalan and autologous peripheral blood stem cell transplantation (PBSCT). Methods: In an original study published in 2006, seven patients with scleromyxedema were treated with high-dose melphalan and autologous PBSCT between April 2000 and November 2003. This follow-up retrospective study evaluated the long-term efficacy and safety of the treatment in five of the original seven patients. Results: Responses were seen in all five patients. Three patients achieved complete responses, and one achieved a partial response. One patient achieved a complete response followed by a partial response after recurrence. Paraprotein levels were stable in two patients. In one patient, paraprotein level was undetectable 10 years following treatment, and in the other two patients, paraprotein levels decreased significantly following treatment. No long-term complications or adverse effects were noted in any of the patients. Conclusions: High-dose melphalan with autologous stem cell transplantation appears to be a safe and effective long-term treatment in patients with scleromyxedema. However, further studies are required to investigate this in larger groups of patients.