淋巴瘤分为何杰金氏病（ＨＬ）和非何杰金氏淋巴瘤（ＮＨＬ）二类。ＮＨＬ常为结外型，最常见于胃肠道，头颈部次之。流行病学研究表明ＮＨＬ似与过度烟酒无关，而在有放射线接触史、接受器官移植后免疫功能抑制、先天性免疫缺陷、艾滋病者中发病率较高。此外，风湿性关节炎、 Lymphomas are classified as either JK (HL) or non-Hodgkin’s lymphoma (NHL). NHL is often extranodal, most common in the gastrointestinal tract, followed by the head and neck. Epidemiological studies have shown that NHL does not seem to be associated with excessive alcohol and tobacco, but has a higher incidence in patients with a history of radiation exposure, immunosuppression after organ transplantation, congenital immunodeficiency, and AIDS. In addition, rheumatoid arthritis,