Large-cell transformation of mycosis fungoides: a case report and diagnostic challenge

Background: Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma, characterized by a slow progression from initial macules or plaques to tumor-stage lesions in advanced phases. Large-cell transformation (LCT) occurs in 10-25% of MF cases and is associated with a worse prognosis. This case highlights the clinical, histological, and therapeutic challenges in diagnosing and managing LCT in MF.