Large Cell Transformation of Mycosis Fungoides Unresponsive to Skin Directed Therapies: A Case Report

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma. Large cell transformation (LCT) is a rare but aggressive evolution occurring in a subset of MF patients and is associated with poor prognosis, especially when CD30 expression and nodal involvement are present. Early recognition and prompt initiation of systemic therapy are crucial.We report a case of a 38-year-old female who presented with widespread hyperpigmented, scaly plaques and systemic symptoms such as fever and weight loss. Clinical evaluation revealed multiple lymphadenopathies. Histopathological analysis of skin biopsy showed large atypical lymphocytes (≥4x size of small lymphocytes), with CD3, CD4 and CD30 positivity, confirming LCT of MF. The patient was staged as IIA (T2N1MOBO). Initial treatment with steroids and narrowband ultraviolet B was ineffective. CHOP chemotherapy was initiated, leading to partial clinical improvement. However, the patient succumbed to sepsis 3 months post-therapy. This case highlights the aggressive nature and poor prognosis of LCT-MF, particularly in young patients with nodal involvement and systemic symptoms. Comparison with similar cases in literature reinforces the need for early systemic therapy and multidisciplinary management to improve outcomes in this challenging variant of cutaneous lymphoma