[Non-Hodgkin lymphoma of the mandible--a case report with differential diagnostic considerations].

Approximately 5% of all malignant lesions are diagnosed as malignant lymphomas, of which 2-3% are localized in the head and neck region. After the squamous cell carcinoma and neoplasms of the salivary glands, malignant lymphomas represent the third most frequent malignant lesion in that region. Malignant lymphomas can be grouped into Hodgkin- and non- Hodgkin lymphomas (NHL) and subdivided into nodal (lymph nodes) and extranodal lymphomas. We present the case of an extranodal non-Hodgkin lymphoma in the left mandible of a 47-year-old woman, who was referred to our department with an unclear swelling, which was supposed to be infectious. After clinical and radiological examination, a biopsy was taken and a CD20 and BCL-6 protein positive non-Hodgkin lymphoma of the large B-cell type (DLBCL) was diagnosed. The patient was treated primarily with immunochemotherapy (R-CHOP protocol) and refused to undergo a subsequent radiotherapy. The 18 months follow-up showed a complete remission of the lymphoma. In this paper, the NHL in the oral and maxillofacial region is presented as a cause of unclear swelling. Important differential diagnostic conditions are discussed.