Treatment-resistant DEK::AFF2 sinonasal squamous cell carcinoma: a case report and review of literature

DEK::AFF2 fusion-associated sinonasal squamous cell carcinoma (SCC) is a rare and recently recognized malignancy, characterized by its deceptively bland histology and aggressive clinical behavior. It is associated with frequent locoregional recurrence and poor response to conventional therapies, including surgery, chemoradiation, and immunotherapy. Although local recurrences of DEK::AFF2 sinonasal SCC have been reported, existing studies are limited to retrospective analyses of initially misdiagnosed tumors. We present the first prospective case of treatment-resistant DEK::AFF2 sinonasal SCC, marked by persistent recurrence despite accurate initial diagnosis, timely initiation of aggressive multimodal therapy, and uninterrupted follow-up. This case highlights the tumor’s aggressive nature even with optimal management, underscoring the need for increased awareness and development of targeted treatment approaches to improve disease control and patient outcomes.