DNA image cytometry in the differential diagnosis of benign and malignant lesions of the bile duct, the pancreatic duct and the papilla of Vater.

UNLABELLED: The value of DNA image cytometry in the differential diagnosis of benign and malignant epithelial lesions was tested analyzing 174 specimens from the biliary tract, the pancreatic ducts and the papilla of Vater. PATIENTS AND METHODS: Cytologic specimens (n=45) or monolayer smears, prepared from three 50 microm thick sections by a cell separation technique (n=129), were stained according to Feulgen. The DNA content of 250 epithelial cells, chosen per random, was determined using a TV-image analysis system CM-1 (Hund, Wetzlar, Germany). The DNA content of 30 lymphocytes served as an internal standard for the normal diploid value in every individual case. Different DNA cytometric parameters and the mean nuclear area were calculated. RESULTS: In comparison with the benign cases (n=120), the mean values of all DNA cytometric variables were markedly increased in the malignant (n=54) (p<0.001). However, a certain overlay of the data distribution had to be considered. Requiring a specificity of >or=95%, sensitivity values up to 87% (mean ploidy) could be obtained. An aneuploid DNA stemline was present in 76% of the tumor cases. The occurrence of 9cEEs were completely restricted to malignant specimens (specificity: 100%), but only present in 50% of the tumor cases. As an additional finding in some benign cases, DNA polyploidy up to 8c could be demonstrated (11/120, 9.2%). CONCLUSION: DNA image cytometry represents a relevant tool in the objective identification of malignant changes of specimens of the biliary tract, the pancreatic duct or the papilla of Vater, if suitable variables are used for DNA data interpretation. However, mainly due to the fact that several cases reveal only slight ploidy changes, a well-preserved DNA ploidy profile does not exclude malignant changes.