[A new system of diagnosis and classification--malignant lymphoma]

Malignant lymphoma is usually divided into Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) according to biological characteristics. Malignant lymphoma in Japan has such the characteristics as few incidence of HD, which is usually favorable in prognosis, and high incidence of NHLs, which have further distinctive features of less incidence of favorable follicular B cell lymphoma and of higher incidence of unfavorable diffuse T cell lymphoma including adult T cell leukemia/lymphoma (ATLL) in comparison with those in western countries. As a recent trend of progress in lymphoma diagnosis an introduction of immunological and molecular biological techniques has given an impact to the previous classification of malignant lymphoma based mainly on morphological criteria. Nowadays, the classification of pathologic type in HD seems to be settled in Rye classification. On the other hand in NHL the LSG classification has been well fixed in Japan and Working Formulation originated in USA has been well used internationally after a historical confusion. In this article a present state of working classification in malignant lymphoma is briefly described and discussed.