Large B-cell Lymphoma with IRF4 Rearrangement in the Nasolacrimal Duct: A Clinicopathological Study of One Case and Literature Review.

Background: Large B-cell lymphoma (LBCL) with interferon regulatory factor 4 (IRF4) rearrangement (LBCL-IRF4) is a rare subtype of LBCL, with a high prevalence in Waldeyer's ring as well as the neck, head and gastrointestinal lymph nodes.

Materials and methods: A patient with 2-month clinical symptoms of nasal obstruction and facial swelling was reported in this short review. A nasal endoscopy examination revealed a neoplasm in the inferior nasal meatus. Both CT and enhanced MRI showed that a soft tissue occupied the nasolacrimal duct, with bone destruction, and extended into the left nasal cavity and left lacrimal gland area. Then, a biopsy of the neoplasm in the inferior nasal meatus was performed.

Results: HE staining results showed that neoplastic cells presented diffuse growth patterns, abundant cytoplasm, vacuole shape, lightly stained nuclei, and irregular nuclear membrane. Immunohistochemistry staining results revealed MUM1(+), Bcl6(+), CD20(+), CD79α(+), and CD10(+). FISH analyses detected positive IRF4 rearrangement. LBCL-IRF4 was diagnosed in the patient. The patient received treatment with four cycles of R-CHOP and two times of rituximab, followed up for 2 years, and finally got complete remission.

Conclusion: For the first time, we summarize the imaging and pathological features, drug treatment, and curative effect of LBCL-IRF4 in the nasolacrimal duct.