[Soft tissue sarcomas. Classifying and/or grading?]

Grading of soft tissue sarcomas cannot substitute for their accurate classification. The latter, according to the historical typing of soft tissue tumors, as proposed by WHO (1969), has to be considered as presumptive for morphological grading. The parameters given for grading are subject to individual bias and artefacts. They are also influenced by the "histogenetic types" of tumors. To achieve some correlations between morphological grading and prognosis, grading parameters (atypia and mitotic activity) have to be weighted differently, according to tumor type. Immunohistochemical methods are helpful in accurate typing of tumors where classification is difficult. The future search will be concerned with more objective methods for grading, including immunohistochemical determination of proliferative markers (similar to Ki67) or flow-through cytophotometry. All efforts are oriented to achieving an optimal correlation between grading parameters on the one hand, and prognostic predictions on the other.