Comparative immunostaining with antibodies against gastric mucin and p53 was performed on 6 cases of minimal deviation adenocarcinoma (MDA) of the uterine cervix. The MDAs consisted of predominant areas of glands lined by extremely well-differentiated tall columnar epithelial cells with little cytological atypia and minor foci of less well-differentiated glandular epithelium with a minor degree of nuclear atypia. Immunostaining for gastric mucin with a monoclonal antibody HIK1083 revealed that all the tumors areas of typical MDA were partly immunoreactive for HIK1083, but the coexisting less well-differentiated glands were essentially negative. Four MDAs focally contained cells with p53 positive nuclei that were located exclusively in the less well-differentiated cells that lacked gastric mucin. In the pelvic lymph nodes in 2 cases, most of the metastatic tumor was less differentiated and a positive reaction for HIK1083 was observed only in small foci of typical MDA. No significant overexpression of p53 was observed in the metastases. Immunohistochemical expression of gastric mucin and p53 may be related to the histological differentiation of MDA, and detection of p53 overexpression may help to identify critical steps in the local progression of MDA.