Mucinous phenotype and CD10 expression of primary adenocarcinoma of the small intestine

Figure 1 Representative CD10-positive small intestinal adenocarcinoma case. A: Well differentiated adenocarcinoma (pointed by arrows) (HE stain, × 12.5); B: CD10-positive glands were seen in the superficial area and the edge of the adenocarcinoma (left, pointed by arrows), while CD10-negative glands were seen in the center or deep area of the tumor (right) (CD10, × 12.5); C, D: These glands in the surface area were positive for CD10 (HE stain and CD10, × 200); E, F: Other glands in the deeper invasive area were negative for CD10 and showed more evident loss of nuclear polarity compared to the CD10-positive glands (HE stain and CD10, × 200).

Figure 2 Representative CD10-negative small intestinal adenocarcinoma case. A: Normal small intestinal mucosa was observed on the right side, whereas the adenocarcinoma was observed on the left side (HE stain, × 12.5); B: Normal mucosa was positive for CD10, but adenocarcinoma was negative for CD10 (CD10, × 12.5); C: The brush border of the normal mucosa was positive for CD10 (CD10, × 100); D: This SIA case showed a poorly differentiated adenocarcinoma (HE satin, × 200); E: Lymphatic permeation was frequently seen (HE stain, × 200); F: The carcinoma cells were negative for CD10 (CD10, × 200).

Figure 3 Small intestinal adenocarcinoma with microsatellite instability-high (case 36). A: The tumor produced abundant mucin (HE stain, × 20); B: The tumor focally showed signet ring-like carcinoma cells (HE stain, × 200); C: The carcinomatous gland was composed of columnar cells with intracytoplasmic mucin (HE stain, × 200); D: These glands were positive for MUC2 (MUC2, × 200); E: positive for MUC5AC (MUC5AC, × 200); F: But negative for MUC6 (MUC6, × 200). In these microsatellites, the tumor was unstable. Microsatellite analysis of paired normal and tumor DNA using G: BAT25; H: BAT26; I: D17S250.