Abstract: Malignant lymphoma complicated by Behcet’s disease (BD) is a rare clinical entity. We report a case of BD
complicated by malignant lymphoma in a 26-year-old male patient. The patient was diagnosed to have terminal ileum
extranodal NK/T-cell lymphoma (nasal type) during treatment for BD with cyclophosphamide (CTX), immunoregulants and
biological agents. This is the first case reported in China and the second case globally. The pathogenesis of BD complicated by
malignant lymphoma remains unclear. We reviewed the relevant literatures to summarize the clinical characteristics of BD
complicated by extranodal NK/T-cell lymphoma (nasal type) and discuss the possible pathogenesis in light of immunology, EB
virus infection and medications.