Lymphoma is the most common form of blood cancer. Hodgkin lymphomaand non-Hodgkin lymphoma (NHL) are the two major forms of lymphoma. B lymphocytes (B cells) and T lymphocytes (T cells) are the two typesof lymphocytes that can develop into lymphomas. B-cell lymphomas aremore common than T-cell lymphomas and account for approximately 85%of all NHLs. The most frequent type of NHL is diffuse large B-cell lymphoma (DLBCL). An aggressive type of lymphoma, DLBCL can appear in lymphnodes or outside of the lymphatic system, skin, testes, in the gastrointestinal tract, thyroid gland, breast, bone, or brain. Usually, the first symptomof DLBCL is a painless swelling in the neck, underarms, or groin causedby swollen lymph nodes. Moreover, swelling may be painful for some patients. A 70-year-old male patient who has been reffered to the MarmaraUniversity, Faculty of Dentistry, Oral Diagnosis and Radiology Clinic had acomplaint of a non-healing and constantly enlarging lesion on the anteriormaxillar buccal/palatinal mucosa and the alveolar ridge. Therefore, an incisional biopsy was performed under local anesthesia, and as definite diagnosis, a histopathological examination revealed DLBCL. Consequently, thepatient was referred to the Department of Hematology where the lesionwas treated. The purpose of this study is to present the case of a male patient with DLBCL and give a literature review.