TRANSITIONAL-CELL CARCINOMA - CYTOLOGIC CRITERIA TO IMPROVE DIAGNOSTIC-ACCURACY

The cytologic diagnosis of low-grade transitional cell carcinoma of th e bladder is difficult, and the reported sensitivity of a positive dia gnosis ranges from 0 to 73%, Using regression analysis, our laboratory previously reported the criteria of increased nuclear/cytoplasmic rat ios, irregular nuclear membranes, and cytoplasmic homogeneity as indic ative of low-grade transitional cell carcinoma To examine the validity of these criteria, six observers examined 88 bladder-wash specimens ( 39 transitional cell carcinomas and 49 benign) and, using the selected criteria, graded each wash for the probability of malignancy. Diagnos tic accuracy was measured using the receiver operating characteristic curve and the likelihood ratio, Overall observer accuracy was 76%, the sensitivity of a definitive negative diagnosis was 82%, and the speci ficity of a definitive positive diagnosis was 96%, We conclude that ke y cytologic criteria can be learned and effectively applied with high accuracy. Observer variation in diagnostic categories might reflect di fferent confidence levels and probabilities of transitional cell carci noma.