Tubal metaplasia of the uterine cervix.

Eleven cases of tubal metaplasia of the uterine cervix are presented. These are characterized histologically by architecturally normal endocervical glands containing ciliated or clear cells, nonciliated cells, and intercalary or peg cells, resembling normal tubal mucosa. Transitions from normal to ciliated epithelium within a single gland are frequently seen. Eight of these cases involved endocervical glands near the squamocolumnar junction, and six showed tubal metaplasia along the overlying surface epithelium. Superficial and (in one case) deep endocervical glands were involved. No correlation was found between the presence of tubal metaplasia and the degree of inflammation of the cervix or the presence or extent of squamous metaplasia. Immunohistochemically, the epithelium of tubal metaplasia was negative for carcinoembryonic antigen in five cases studied. In situ squamous carcinoma and a variety of benign glandular lesions, such as microglandular hyperplasia, mesonephric remnants, and endometriosis, were concurrently identified. Two cases also accompanied tubal metaplasia in proliferative and hyperplastic endometria, and tubal metaplasia was seen in the lower uterine segment in five cases. We emphasize that, as with other types of metaplasia, the main significance of recognizing this lesion in the cervix is in not confusing it with early endocervical glandular neoplasia.