Eleven-year experience of low grade lymphoma in Korea (based on REAL classification).

Low grade lymphomas are malignancies of predominantly small lymphocytes that typically have long median survival periods due to low proliferative rates. It is considered an indolent disease, but patients with low grade lymphoma can almost never be cured with conventional treatment. New low- grade lymphoma entities have been classified by the International Lymphoma Study Group (ILSG) and are also categorized into the Revised European American Lymphoma (REAL) classification. The REAL classification utilizes a multiparameter definition of clinico-pathologic and biologic entities. According to this classification, we investigated the incidence, various clinical characteristics, treatment outcome and prognostic factors of low grade lymphoma. Many clinical characteristics of low grade lymphoma in Korea differed from those of Western countries, especially in the incidence, therapeutic outcome and prognostic factors. In Korea, although the general incidence of low grade lymphoma is relatively low, the relative number of mucosa-associated lymphoid tissue lymphoma (MALToma) is very high, and the overall survival rate is better than that reported of Western countries. Thus, further investigation on treatment outcome and prognosis of low grade lymphoma entities, other than mucosa- associated lymphoid tissue lymphoma, are warranted.