Will a tumor metastasize? Quantitate, semi-quantitate or pseudo-quantitate? A brief review of the microscopic prediction of tumor metastasis.

This review examines ways in which histopathologists can attempt to predict whether a neoplasm will metastasize by microscopic examination of surgically removed samples of human neoplasms. These include qualitative description, semi-quantitative analysis of differentiation and proliferation, or of the nature of the edge of the neoplasm, and quantitative analysis of mitotic counts. More recently measurement of DNA content, analysis of DNA turnover, measurement of proliferation antigens, measurement of nucleolar organizing areas, counting nucleoli, morphometry of nuclei and identification of genetic change have become possible. There is no test capable of uniform accurate prediction of prognosis. In certain types of neoplasms in individual sites useful prognostic information can be obtained either by rigorous semi-quantitative microscopic analysis or by quantitative microscopical analysis. There is still doubt as to whether newer quantitative techniques will perform uniformly better than older semi-quantitative techniques. The simple subjective statement "high-grade malignancy, average malignancy, low malignancy" is better than elaborate non-reproducible pseudo-quantitation.