Case Report Open Access 15 Sinocutaneous fistula is a rare complication of chronic rhinosinusitis (CRS), most commonly involving the frontal sinus, with maxillary sinus involvement being uncommon and typically associated with trauma, surgery, or odontogenic infection. We report a rare case of a maxillary sinocutaneous fistula secondary to chronic maxillary rhinosinusitis in the absence of trauma, prior surgical intervention, fungal infection, or neoplasia. The condition resulted from longstanding inflammation with associated osteitis and cortical erosion of the maxillary sinus wall, leading to abnormal communication with the overlying facial skin. Diagnosis was established through clinical evaluation and contrast - enhanced computed tomography of the paranasal sinuses. Definitive management consisted of functional endoscopic sinus surgery with complete excision of the fistulous tract and primary multilayered closure. This case underscores the potential for chronic inflammatory sinonasal disease to cause rare bony complications and highlights the importance of considering CRS in the differential diagnosis of persistent facial cutaneous fistulae

Case Report Open Access 15 Sinocutaneous fistula is a rare complication of chronic rhinosinusitis (CRS), most commonly involving the frontal sinus, with maxillary sinus involvement being uncommon and typically associated with trauma, surgery, or odontogenic infection. We report a rare case of a maxillary sinocutaneous fistula secondary to chronic maxillary rhinosinusitis in the absence of trauma, prior surgical intervention, fungal infection, or neoplasia. The condition resulted from longstanding inflammation with associated osteitis and cortical erosion of the maxillary sinus wall, leading to abnormal communication with the overlying facial skin. Diagnosis was established through clinical evaluation and contrast - enhanced computed tomography of the paranasal sinuses. Definitive management consisted of functional endoscopic sinus surgery with complete excision of the fistulous tract and primary multilayered closure. This case underscores the potential for chronic inflammatory sinonasal disease to cause rare bony complications and highlights the importance of considering CRS in the differential diagnosis of persistent facial cutaneous fistulae