The cytologic diagnosis of adenocarcinoma in situ of the cervix uteri and related lesions. III. Pitfalls in diagnosis.

Potential pitfalls in the cytologic diagnosis of adenocarcinoma in situ (AIS) of the cervix are illustrated by the presentation of three cases of benign cervical lesions initially diagnosed as AIS: cervical endometriosis, tubal metaplasia of the endocervix and changes due to a previous biopsy. The differential diagnosis of endocervical glandular abnormalities is discussed.