From Inflammation to Malignancy: Diagnosing Ocular Adnexal Diffuse Large B-Cell Lymphoma Beyond Dacryocystitis.

This case report discusses a 16-year-old male patient with a history of recurrent allergic rhinitis and sinusitis, who initially presented with left eyelid swelling, proptosis, and progressive facial edema extending from the left medial canthus to the nasal bridge. He was treated for nearly a year under the working diagnosis of chronic left dacryocystitis with multiple courses of topical, oral, and intravenous antibiotics. However, the patient developed worsening proptosis, progressive left-sided vision loss, and left submandibular lymphadenopathy, which ultimately guided the diagnostic focus toward ocular adnexal lymphoma (OAL) involving the left orbit. Despite multiple imaging studies and histopathological assessments, it took nearly a year to identify the exact pathology. This case report details the diagnostic journey, treatment strategies, and interventions employed to preserve the patient's vision, ultimately enabling him to resume normal activities. We emphasize that in cases of chronic, unresponsive dacryocystitis, ocular adnexal lymphoma should be considered in the differential diagnosis. Early surgical intervention plays a critical role in optimizing visual outcomes and should be pursued to avoid further morbidity associated with delayed diagnosis.