Comparative cytologic features of adenocarcinoma in situ of the uterine cervix.

The cytologic findings in 30 cases of adenocarcinoma in situ (AIS) and related lesions of the cervix were compared with those in 13 cases of cervical invasive adenocarcinoma and 8 cases of cervical nonneoplastic conditions that mimicked AIS cytologically. Although there was considerable overlap, the presence of large cells with irregular nuclei and uneven chromatin distribution in smears containing no normal endocervical cells helped to distinguish invasive adenocarcinoma from AIS. The presence of "feathering," rosettes, mitotic figures and very crowded nuclei with scant cytoplasm and without cilia helped distinguish AIS from benign conditions.