Type of Preparation: Conventional Magnification: High Interpretation: Endocervical adenocarcinoma in situ (AIS) Cytomorphologic Criteria: Cluster of cells with crowded overlapping oval nuclei that show hyperchromasia and evenly distributed by coarsely granular chromatin. Smear background is clean. Explanatory Notes: Nuclear crowding and overlapping, hyperchromasia and evenly distributed granular chromatin are classic features of AIS. Follow-up: Endocervical adenocarcinoma in situ