A Case of Maxillary Squamous Cell Carcinoma Transformed to Large Cell Neuroendocrine Carcinoma After Concurrent Chemoradiotherapy; [항암방사선 치료 후 대세포신경내분비암으로 전환된 상악동 편평세포암 1예]

Abstract

Large cell neuroendocrine carcinoma (LCNEC) is a poorly differentiated neuroendocrine carcinoma that typically arises in the lung. Because of its rarity and poor prognosis, standardized treatment has not been established yet. A 53-year-old male was initially diagnosed as a maxillary sinus squamous cell carcinoma (SCC) arising from inverted papilloma (clinical stage of T4bN2bM0, stage IVb), and underwent concurrent chemoradiotherapy. After achieving complete remission for 3 years, recurrent tumors were found, of whom the pathologic diagnosis turned out to be LCNEC. He underwent endoscopic transnasal tumor extirpation, followed by adjuvant concurrent chemoradiotherapy. Until postoperative 12 months, he showed no evidence of recurrence. To the best of our knowledge, this is the first report of maxillary SCC transformed to LCNEC after chemoradiotherapy. Copyright © 2023 Korean Society of Otorhinolaryngology-Head and Neck Surgery.