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 with punctate or occasionally prominent nucleoli. 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.