Abstract
Inverted sinonasal papillomas, also referred to as Schneiderian papillomas, are benign tumors originating from the Schneiderian membrane that lines the nasal cavity and paranasal sinuses. They frequently display an endophytic growth pattern, in which the stroma beneath is invaded by epithelial cells. The exact cause of inverted sinonasal papillomas is unknown, but several theories have been offered. The most widely accepted theory states that these tumours arise from the metaplasia of the respiratory epithelium into a stratified squamous epithelium. This metaplastic process is thought to be brought on by irritant exposure, chronic inflammation, or viral infections like the human papillomavirus (HPV). While inverted sinonasal papillomas commonly arise from the paranasal sinuses and lateral walls of the nasal cavity, their occurrence from the nasal septum is relatively rare. Additionally, although inverted sinonasal papillomas are typically benign, they can exhibit locally aggressive behaviour and damage nearby structures. The histopathological examination revealed nuclear atypia, which raises questions about the potential for malignant transformation. We describe a rare case of an inverted sinonasal papilloma that developed from the nasal septum. The tumour spread into the septum's anterior cartilaginous region, causing the cartilage to deteriorate and develop mucosal defects. The rarity of an inverted sinonasal papilloma arising from the nasal septum along with its impact on cartilaginous septum is discussed. Careful monitoring and prolonged follow-up are therefore necessary to spot any signs of recurrence or malignant changes.