Development of a primary cutaneous CD30(+) anaplastic large-cell T-cell lymphoma during treatment of multiple sclerosis with fingolimod

Background: The appearance of solid tumors und lymphomas during treatment with fingolimod was observed in studies and has been described in case reports. Objective: To report a case of primary cutaneous CD30(+) anaplastic large-cell T-cell lymphoma during treatment of multiple sclerosis (MS) with fingolimod. Methods: Case study. Results: Our patient developed a lymphoma a few weeks after initialization of therapy with fingolimod; 5weeks after discontinuation of treatment the lesions resolved. Conclusion: Causality of fingolimod is indicated by the fact that the skin lesions appeared after commencement of treatment and resolved after discontinuation of therapy. This case serves as a reminder of the potential side effects of fingolimod.