Discrimination between dysplastic and malignant epithelium of the ampulla of vater based on quantitative image cytometric data.

OBJECTIVE

To assess the ability to associate histopathologic grading with objective criteria obtained by nuclear image cytometry in epithelium of the ampulla of Vater.

STUDY

DESIGN

Forty-one resected ampullary specimens were studied, including 8 dysplastic ampullomas together with 22 well-differentiated and 11 poorly differentiated ampullary adenocarcinomas. The nuclei were Feulgen stained and analyzed using a computer-assisted microscope, which generated 38 quantitative variables describing chromatin texture and nuclear DNA content (DNA ploidy level). These variables were explored by discriminant analysis to determine the most stable and informative variables. Univariate analysis was performed on the four most informative ones. The whole set of variables was also subjected to principal component analysis in order to characterize intragroup and intergroup heterogeneity.

RESULTS

The univariate analysis defined two morphonuclear variables (related to nuclear chromatin distribution) discriminating between dysplasia and well-differentiated cancers. Aneuploidy occurrence was associated with discrimination between well-differentiated and poorly differentiated cancers.

CONCLUSION

While alterations in chromatin distribution may be an early event in the malignant degeneration of this epithelium, alterations in nuclear DNA content should correspond to a later phenomenon. Quantification of these features can be exploited to assist in diagnosis.