Abstract
Primary intraosseous non-Hodgkin lymphoma in the mandible is uncommon, representing about 0.6% of all extranodal lymphomas. We present the case of a 51-year-old male with a 4-month complaint of mandibular swelling and paresthesia, which had been previously submitted to an unsuccessful periodontal treatment. The intra-oral evaluation showed an extensive swelling with teeth mobility in the right mandible body. The panoramic radiography and computed tomography images showed an extensive osteolytic lesion. An incisional biopsy was performed and the histopathological and immunohistochemical analysis established the diagnosis of diffuse large B-cell lymphoma. The treatment included six cycles of chemotherapy with complete remission. The patient is under the seventh month of follow-up with no evidence of relapse. Although uncommon in the oral cavity, lymphoma should be considered in the differential diagnosis.