The cells in the photomicrograph are uniform and small, with low N:C ratios. The cells are cohesive and are arranged in flat sheets with a honeycomb pattern. In contrast, cytomorphologic features of aspirates of pancreatic adenocarcinoma include increased cellularity; sheets of disorganized cells (“drunken” honeycomb) with overlapping, pleomorphic nuclei with irregular nuclear membranes; coarse and irregular chromatin; and increased N:C ratios. Three-dimensional clusters, single malignant cells, and mitotic figures may also be present.
Gastric epithelium may be virtually indistinguishable from benign pancreatic ductal epithelium. Goblet cells are usually not seen.
Cells derived from small intestinal epithelium usually appear as flat sheets of cohesive, uniform cells in a honeycomb arrangement. Small intestinal epithelium may be recognized by the presence of goblet cells, as depicted in the photomicrograph.
Smears from low grade MCN are grossly gelatinous and usually hypocellular and show flat, usually organized, sheets of bland mucinous epithelium in a background of abundant thick mucin. The cells are columnar, with mucin-filled cytoplasmic vacuoles and basally located nuclei. Differentiating benign gastric and intestinal mucosal epithelial cells from mucinous neoplasms can be difficult. One helpful feature is the presence of thicker and more abundant mucin in association with MCN.
Benign intestinal epithelium can be very similar to benign pancreatic ductal epithelium; however, pancreatic ductal epithelium has no goblet cells.
