A CLINICOPATHOLOGICAL STUDY OF VILLOUS ADENOMA OF LARGE BOWEL WITH PCNA LABELING INDEX

Abstract

Using the labeling index of proliferating cell nuclear antigen (PCNA), we performed a clinicopathological study of 21 villous adenomas of the large bowel. Patients were 12 men and 8 women (mean age, 67.2 years) . Most tumors were located in the sigmoid colon. Large tumors tended to be villous adenoma with carcinoma, of which 61.9% had invaded the mucosa or submucosa. In villous adenoma with carcinoma, the PCNA labeling index in areas of villous adenoma and areas of carcinoma differed. However, there was no difference in the labeling indices of areas of villous adenomas with and without carcinoma. In this study most PCNA-positive cells were in focal areas of dysplasia. When colonoscopic biopsy is performed, taking specimens from areas of carcinoma is not necessary. However, when a tumor is diagnosed as villous adenoma, many biopsies must be performed. In addition, we must investigate villous adenomas on the basis of results of biopsies and other factors, such as tumor diameter.