THE GREAT MIMIC- SINONASAL MELANOMA VERSUS SINONASAL POLYPOSIS

Sinonasal mucosal melanoma (SNMM) is a rare, highly aggressive tumour deriving from melanocytes within the mucosal lining of the nasal cavity and paranasal sinuses[1][2]. Due to its often subtle and nonspecific clinical manifestations, Sinonasal melanoma can be mistaken for benign inflammatory conditions such as sinonasal polyposis, delaying the diagnosis and treatment[3][4]. We discuss a 55-year-old male who presented with complaints of intermittent right-sided nasal bleeding and nasal obstruction for over three months. Early clinical and imaging findings suggested an infected sinonasal polyp, but histopathological evaluation ultimately confirmed Sinonasal mucosal melanoma , with immunohistochemistry demonstrating HMB-45 positivity and negative results for p40, cytokeratin, and synaptophysin. Postoperative PET-CT found no residual disease, and the patient remains recurrence-free one year post-treatment. This case highlights the diagnostic challenges posed by Sinonasal melanomas and emphasizes the necessity of early biopsy and immunohistochemical analysis for accurate identification and optimal management[2][4].