A Case of Diffuse Large B Cell Lymphoma (DLBCL) with Lower Lip Paralysis As the First Manifestation

Case reports on malignant lymphoma in the oral and maxillofacial region are rare, and most describe extranodal lymphomas. We report a case of diffuse large B-cell lymphoma (DLBCL) that invaded into the right mental nerve of a 78-year-old woman, who initially presented with right lower lip palsy and pain. We diagnosed severe marginal periodontitis of the right lower first premolar, and planned to extract the tooth in 3 months because she had been taking bisphosphonates for more than 3 years. Two months after the first visit, her palsy and pain became more severe. The right lower lip was red and swollen, and a bead-like mass had developed around the mental foramen. Biopsy of the swollen mental nerve showed DLBCL. Systemic screening results showed that the stage was Ⅳ A. The patient was given chemotherapy with rituximab, tetrahydropyranyl adriamycin, and cyclophosphamide (R-THP-COP) combined with radiotherapy to the left cervical lesion. The redness, swelling, and paralysis of the right lower lip disappeared, and there have been no signs of recurrence in the 13 months after treatment.