Three cases of non-Hodgkin malignant lymphoma (LMNH in text) of the mandible are described, and findings compared with those reported in the literature. The mean age of patients was 46 years, without any significant male preponderance (sex ratio: 1.19), the preferential localization being the horizontal branch. Detection of the lesion was, by decreasing order of frequency, based on: mandibular tumefaction, pain, local neurologic disorders and dental mobility. Diagnosis was confirmed by histology of a deep biopsy specimen, facilitated by immunohistochemical techniques: the most frequently encountered histologic type was the diffuse large cell type (group G of the international clinical classification). Diagnosis was difficult because of the similarity of the presentation with other dental diseases and the difficulty of histologic interpretation. The principal differential diagnoses are osteomyelitis, sarcoma and carcinoma, the first one raising the risk of a long delay in diagnosis, the others of unnecessary mutilating surgery. The lesion was localized in more than half the cases, without accompanying enlarged cervical glands or metastatic visceral invasion. Treatment was by radiotherapy, usually in association with multiple chemotherapy because of the high incidence of intermediate or elevated histologic malignancy. Global prognosis was good (5 year total clinical remission rate of more than 60%), the poorest prognostic factor being metastatic spread.
