Type of Preparation: Conventional Magnification: High Interpretation: Endocervical adenocarcinoma in situ Cytomorphologic Criteria: Cluster of cells with enlarged, variably-sized round or oval nuclei with prominent nucleoli. A mitotic figure is also noted. Explanatory Notes: AIS may occasionally show prominent nucleoli, raising the question of invasive endocervical adenocarcinoma. Follow-up: Endocervical adenocarcinoma in situ