Morphometric analysis of gallbladder adenocarcinoma: discrimination between carcinoma and dysplasia.

To characterize the cytological features of well differentiated adenocarcinoma of the gallbladder, a comparative morphometric analysis was made using 35 histologically classified cases of invasive well differentiated adenocarcinoma, 13 cases of mild dysplasia, 19 cases of severe dysplasia, and 22 control gallbladders. The variables analyzed were nucleocytoplasmic (N/C) ratio and nuclear area (N.A.). Both the mean values of N/C ratio and N.A. demonstrated a progressive increase from control to mild dysplasia, to severe dysplasia and to carcinoma. The differences were statistically significantly different. Discriminant analysis was made with a set for learning and a set for testing, selected from the 89 lesions with random numbers. Using this discriminant function, all the cases except one carcinoma were discriminated as carcinoma, and all the cases of control, adenoma, and mild dysplasia were discriminated as benign lesions. However, cases of severe dysplasia were subdivided into benign or malignant. These results indicate that morphometric analysis clearly differentiates carcinomas from benign lesions, and that the dysplastic mucosal lesions can be divided into benign and malignant, although some difficult borderline lesions exist.