Lacrimal Sac Diffuse Large B-Cell Lymphoma Presenting as Sudden Onset Binocular Diplopia: A Case Report

Introduction: Diffuse Large B Cell Lymphoma (DLBCL) is a prevalent subtype of Non-Hodgkin Lymphoma (NHL) affecting predominantly elderly individuals. Lacrimal gland DLBCL is rare, posing diagnostic challenges due to its atypical presentation. Case Presentation: A 68-year-old man with a history of hypertension, hyperlipidemia, and a small pituitary gland tumor presented with sudden-onset binocular diplopia and right eye blurry vision. MRI of the brain revealed enhancing soft tissue in right superolateral orbit inseperable from the lacrimal gland and extending medially to the right superior rectus muscle and soft tissue. Further scanning showed widespread metastasis to bilateral retroperitoneal lymph nodes, adrenal gland, spine, and lymph nodes in the neck. Biopsy of the lacrimal gland confirmed DLBCL. The patient was started on chemotherapy consisting of methotrexate and rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone. Conclusion: Primary lacrimal gland DLBCL is a rare and diagnostically challenging entity. The delayed diagnosis often stems from the resemblance of its clinical manifestations to more benign conditions such as dacryocystitis, dacryostenosis, or mucocele. Timely recognition and accurate diagnosis are essential for initiating appropriate treatment and improving patient outcomes.