General principles of grading lesions in diagnostic histopathology.

The principles behind grading histological samples by any method describing them is outlined. The estimation of the variation of measurement allows the number of falsely graded cases to be estimated, and thus makes it possible to compare grading methods in respect to their sensitivity, specificity, and efficiency. The approach is especially suitable for situations in which measurements are made on histological sections, but can also be applied in traditional subjective grading. The approach also makes it possible to estimate the grading performance by such methods as DNA-cytometry, flow cytometry, immunohistochemistry, and nucleic acid in situ hybridisation.