Abstract
Mycosis fungoides (MF), the most common type of primary cutaneous T-cell lymphoma, presents a formidable diagnostic challenge, particularly in its early stages and in patients with darker skin tones. The initial lesion in this case was diagnosed as cellulitis, a common bacterial skin infection, despite the absence of significant pain, a less typical but documented presentation of cellulitis, which can also manifest as burning, itching, or mere redness and swelling without pronounced tenderness. This case report details the diagnostic journey from initial misdiagnosis to eventual identification of MF in a 57-year-old woman. The report emphasizes the overlapping clinical and histopathological features between MF and more prevalent inflammatory dermatoses, which often lead to diagnostic delays. By including a detailed timeline, comprehensive patient history, explicit diagnostic reasoning, and informed consent declaration, this report aims to highlight the unique barriers to MF diagnosis, especially in individuals with darker skin, and to provide practical insights for clinicians navigating similar diagnostic dilemmas. The rarity and subtlety of early MF, compounded by its ability to mimic benign conditions such as eczema, psoriasis, and cellulitis, underscore the need for heightened clinical suspicion and multidisciplinary collaboration in dermatologic practice.