Abstract
We analyzed the metaplastic changes of one hundred and fifity lesions of gallbladder carcinoma (including 32 early lesions). Metaplasia in the carcinoma was classified into three types (proper epithelium type carcinoma, metaplastic type carcinoma and unclassified type carcinoma). Metaplastic type carcinoma was subdivided into gastric type metaplasia, (comprised of pseudo-pyloric gland type and surface mucous cell type), intestinal type metaplasia and endocrine cell type metaplasia. Fifteen lesions were of the proper epithelium type,105 metaplastic type and 30unclassified type. Among the lesions of metaplastic type carcinoma, the incidence of gastric type, especially of pseudo-pyloric gland type, was higher than that of the other types of metaplasia. Metaplasia was prevalent in the surrounding mucosa as well as in the carcinoma. Considering the histological type and depth of invasion, the incidence of metaplasia was higher in advanced papillary carcinoma (PA) and advanced well differentiated tubular adenocarcinoma (WTA). However, incidence of metaplasia in early PA was significantly lower than that in early WTA. On the other hand, the incidence of metaplasia was higher in WTA even in the early stage, including five small lesions, which were less than 1cm in size. These findings suggest that metaplasia is prevalent in gallbladder carcinoma and there are two different metaplastic types of the carcinomas, one derived from the proper epithelium that develops itself into metaplastic type carcinoma, and the other originally from metaplastic epithelium.
