Disseminated tumor cells versus micrometastasis: Definitions and problems

The finding of single tumor cells or small tumor cell groups in the lymph a nd blood (including bone marrow aspirations) should be designated as isolat ed or disseminated tumor cells. The UICC (1992) recommended to identify suc h findings by the addition of "(i)" (for isolated tumor cells). In contrast , micrometastasis (2 mm or less) should be indicated by the addition of "(m i)": Before introduction of the examination of lymph nodes or bone marrow a psirations regarding isolated (disseminated) tumor cells the methods have t o be standardized and the clinical relevance (independent prognostic signif icance, assistance in selection of patients for adjuvant treatment) has to be evaluated in prospective large scale studies.