Abstract

This study was performed with the purpose of histochemical comparison of CEA and EMA localization between adenoma and well-differentiated adenocarcinoma of the stomach. The specimen was 12 lesions of adenoma and 15 foci of well-differentiated adenocarcinoma of the stomach. The markers in neoplastic tissue and neighbouring mucosa of the tumors were examined in paraffin sections using peroxidase-antiperoxidase method. The data obtained were evaluated statistically. The results were summarized as follows: 1) In 12 lesions of stomach adenoma, the positive reaction to CEA was seen in 3 lesions (20.0%), and to EMA in 10 lesions (83.3%). The positive rate of CEA in adenoma was lower than that of the neighbouring normal mucosa, but the positive rate of EMA was similar between the two. 2) In 15 foci of well-differentiated adenocarcinoma of the stomach, the positive reaction to CEA was seen in 13 foci (86.7%), and to EMA in 12 foci (80.0%). The positive rate of CEA in well-differentiated adenocarcinoma was higher than that of the neighbouring normal mucosa, while the positive rate of EMA was similar to each other. 3) Immunoreactivity to CEA in adenocarcinoma showed good positive correlation with the development of cuticular border of the neoplastic glands, while reactivity to EMA in adenocarcinoma was not related with the development of cuticular border. 4) The positive rate and intensity of CEA reaction in adenocarcinoma were higher than those in adenoma, but the positive rate and reactiveity of EMA were similar to those of adenoma. 5) The positive rate of CEA or EMA in the neighbouring mucosa of adenoma was not different compared with those in the neighbouring mucosa of adenocarcinoma. With the above results, it is concluded that adenoma and adenocarcinoma of the stomach may be different each other, biologically, and further more, it is presumable that adenoma may not be a premalignant lesions. It is considered that examination of CEA immunoreactivity may be helpful in differentiated of adenoma from well-differentiated adenocarcinoma, in most cases.

• Keywords: CEA;EMA