Malignant lymphoma of the tonsil in a patient with Behçet's disease.

Several connective tissue diseases such as rheumatoid arthritis and polymyositis are associated with cancer. In contrast, cancer is rarely reported in patients with Behçet disease. We report a case of lymphoma during the course of Behçet disease. Etiopathogenic factors are discussed. A 46-year-old man with a 14-year history of Behçet disease was diagnosed with non-Hodgkin malignant lymphoma of the right tonsil. He met international criteria for Behçet disease, which manifested as refractory oral ulcers requiring dapsone treatment. He achieved a complete remission of the lymphoma after three chemotherapy courses and local radiation therapy (45 Gy). At last follow-up 4 years later, he was still in complete remission.