Abnormal endocervical cells. Really abnormal? Really endocervical?

With the increasing incidence of endocervical adenocarcinoma, cytopathologists must distinguish between benign dysplastic and malignant endocervical cells. For this reason, the authors began a retrospective review of 44 cytology specimens initially interpreted as "abnormal endocervical cells of uncertain significance" and of 10 endocervical carcinomas. Cytologic specimens were categorized according to tissue into three groups: reactive cells (9), abnormalities associated with squamous intraepithelial lesions (17 low grade, 18 high grade), and adenocarcinoma (10). Reactive cells were monolayered, with demarcated cytoplasm and bland nuclei. Abnormal cells from squamous intraepithelial lesions showed crowding and irregular nuclei with smudgy or granular chromatin. Cells from adenocarcinoma showed multilayering and nuclei with clumped chromatin and occasional mitoses. On reexamination, numerous cells were found to be of metaplastic rather than endocervical origin. Surprisingly, the presence of abnormal metaplastic or endocervical cells sometimes was the only indicator of associated squamous intraepithelial lesion.