ABSTRACT
Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-hodgkin's lymphoma. In oral cavity represents approximately 2% of all malignancies. Case presentation: This report describes a rare mandibular involvement of DLBCL. A 56 year-old man was referred for evaluation of left mandible pain. In the anamnesis, the patient informed to be treating tooth pain in lasting 6 months. On oral evaluation, an intense mobility of the left mandibular second molar and a swelling in posterior left mandible were observed. Computed tomography showed a large osteolytic lesion affecting both mandibular body and ramus. An incisional biopsy was performed and according to histopathological and imumnohistochemical features, DLBCL was diagnosed. The treatment consisted of 8 cycles of R-CHOP and adjuvant radiotherapy. He is asymptomatic after 6 years. Conclusion: This case showed a rare bone presentation of DLBCL and such tumor should be considered as differential diagnosis of osteolytic lesion of the mandible.