RESUMEN
BACKGROUND: There are multiple case reports in the literature describing an association between fingolimod and cutaneous neoplasms. OBJECTIVE: Investigate and report a case of a primary mediastinal large B-cell lymphoma in a patient on fingolimod for Relapsing-Remitting Multiple Sclerosis (RRMS). METHODS: Case Report. RESULTS: The patient developed a primary mediastinal large B-cell lymphoma after seven years of treatment with fingolimod. The patient is currently in complete remission after cessation of treatment, surgical resection, chemotherapy, and radiation therapy. CONCLUSION: This case report highlights the first primary mediastinal large B-cell lymphoma associated with fingolimod treatment. It should be considered a rare, but potential adverse effect of fingolimod.