Case selection: gastric tumor with low-grade nuclear atypia (not typical well-, moderately- or poorly-differentiated adenocarcinoma)
Histologic features seen in these tumors:
(1) pit and glandular anastomosis
(2) spiky glands (gland with sharp projects and/or sharp edges)
(3) distended glands
(4) discohesive cells
(5) abortive glands
(6) glandular outgrowth (very small glandular structure emerging from a larger gland)
Examples of these features are shown in Figure 1 on page 1622.
The diagnosis of a very well-differentiated gastric adenocarcinoma of the intestinal type required the presence of >= 3 of these histologic features.
Markers for immunophenotyping the tumor:
(1) gastric: MUC5AC and MUC6
(2) intestinal: MUC2, CD10, CDX2
Tumors with the mixed gastric and intestinal immunophenotype was more likely to have discohesive cells, and tumors with discohesive cells were more likely to behave in an aggressive manner.
Tumors with the pure intestinal immunophenotype behave as low grade tumors.
