Diffuse Large B-Cell Lymphoma of the Ethmoid Sinus With Orbital Invasion: A Case Report.

Diffuse large B-cell lymphoma (DLBCL) rarely involves the paranasal sinuses, and ethmoidal localization with orbital extension is exceptional. We report the case of a 76-year-old patient presenting with progressive nasal obstruction and epiphora. Imaging revealed an ethmoidal mass with orbital invasion. Histopathological examination confirmed the diagnosis of DLBCL. The patient was referred to the medical oncology department for systemic immunochemotherapy followed by consolidative radiotherapy. No surgical intervention was performed. This case emphasizes the need to consider lymphoma in the differential diagnosis of aggressive sinonasal masses with orbital involvement. Early diagnosis and appropriate oncologic management are crucial for optimal outcomes.