Complete response of unilateral primary lacrimal sac diffuse large B-cell lymphoma treated without radiotherapy in an adult: A rare case report and review of the literature.

Diffuse large B-cell lymphoma (DLBCL) manifests extranodally in one-third of non-Hodgkin lymphoma (NHL) cases. However, primary DLBCL of the lacrimal sac is very rare. A 54-year-old man presented with a 5-month history of right-sided epiphora. He visited three private clinics and was misdiagnosed with conjunctivitis. Later, a painless mass in the right lacrimal area prompted an MRI scan followed by a CT scan, which suggested a lacrimal sac mass. The mass was surgically excised, and histopathology and immunohistochemistry revealed DLBCL. A PET/CT scan was done instead of bone marrow biopsy, which excluded systemic lymphomatous involvement, confirming the diagnosis of primary right lacrimal sac DLBCL. The patient received six standard cycles of the R-CHOP regimen. Although no radiotherapy was used, CT findings after the completion of the 4th cycle showed a complete response (CR), which was maintained in a follow-up CT scan 2 months after chemotherapy completion. Despite the rarity of the tumor, it should be considered in the differential diagnosis of long-standing or unresponsive inflammatory conditions. Radiotherapy-free management could achieve CR in limited-stage DLBCL.