A statistical approach to the histopathologic diagnosis of synovitis.

Synovial tissue from 393 operations on diseased joints were scored for each of 37 histopathologic variables; the patients fell into 10 clinically defined diagnostic categories. The five most populous of these diagnostic groups provided a data set for calculating diagnoses based on histopathologic findings. For each pair of clinical diagnostic categories we derived a linear discriminant function dependent solely on the histopathologic assessments. The functions gave a numerical score for segregating each case into one of the diagnostic categories. The histopathology based diagnoses agreed with the clinical diagnoses in 54 to 78 per cent of the cases. Illustrations of the application of this technique are presented.