Abstract
Recent topics regarding childhood non-Hodgkin's lymphoma (NHL) are reviewed. First is a new classification system of malignant lymphoma proposed by the International Lymphoma Study Group : Revised European-American Lymphoma (REAL) classification, which incorporates recent knowledge about the morphological, immunophenotypic and genetic information of different lymphomas. In contrast to various types of lymphomas in adults, childhood NHL is primarily limited to three histologic types (lymphoblastic-LBL, small noncleaved-SNC and diffuse large-cell DLC). Therefore, the clinical utility of the REAL classification for childhood NHL must await the accumulation of our experiences. The second topic is the current knowledge on molecular abnormality in NHL. The recent developments in molecular assays have identified various genetic abnormalities which underlie the three histologic types of childhood NHL. The door has been opened to understand the precise link between molecular alterations and the clinical behavior of each subtype of NHL. Thirdly, significant progress in the treatment of NHL is reviewed. A dramatic improvement in the cure rate of children with SNC has been obtained since 1985. More specific approaches with shortened and more doseintensive use of cyclophosphamide, methotrexate and intensive intrathecal therapy have produced event-free survival rates of 70-80% for stage III/IV SNC. Finally, the development of second leukemia (acute myeloid leukemia) among children with NHL is discussed. Although the exact pathogenesis is unknown, accumulated data suggests the use of etoposide on a certain schedule (twice weekly) is the most important risk factor.
