[Benign (reactive) lymphoproliferation or malignant lymphoma?].

Pre-stages and early stages of malignant Non-Hodgkin's-lymphomas mark the border area between benign, reactive lymphoproliferation and neoplastic transformation. The advances of immunological classification of lymphoid cells with monoclonal antibodies and molecular genetic analysis have contributed to our present knowledge of pathomorphology, pathophysiology and nosology of malignant lymphomas. The stepwise evolution between polyclonal reactive lymphoproliferation and clonal autonomous growth in malignant lymphomas are presented by discussion of the mucosa-associated lymphomas (MALT-lymphomas) and typical lymphoproliferative diseases.