Mucinous Borderline Tumor
Cytologic atypia in a mucinous borderline tumor (MBT) - intestinal type: The upper half of the image shows glands lined by a single layer of columnar mucinous cells admixed with goblet cells. The mucinous cells have basally located nuclei lacking atypia. The lower half shows a more complex architecture with papillary and cribriform areas. There is greater degree of cytologic atypia consisting of nuclear enlargement and hyperchromasia. The appearance resembles adenomatous colonic polyp. High-grade nuclear features are not seen. A few scattered mitotic figures are present. There is no destructive stromal invasion.