Small undifferentiated intramucosal gastric cancer with lymph-node metastasis: Case report

Figure 1 Pre-treatment endoscopic examination. Esophagogastroduodenoscopy revealed pale depressed mucosal lesion on anterior wall of middle gastric body approximately 15 mm in size with no ulcerative finding and non-atrophic background mucosa. A: Conventional white light endoscopy; B: With indigo-carmine dye staining.

Figure 2 Surgically resected specimen. A: Formalin-fixed specimen from pylorus preserving gastrectomy; B: Panoramic view of lesion with hematoxylin and eosin staining. Mucosal lesion 15 mm × 12 mm in size with no ulcer finding and pink lines corresponding to lesion depression (hematoxylin and eosin staining, × 1).

Figure 3 Histopathological findings. A: Panoramic view with hematoxylin and eosin staining (× 1); B: Signet-ring cell carcinoma identified at lesion edge (green frame in A, × 40); C: Moderately to poorly differentiated adenocarcinoma limited to mucosa visible in lesion center. Low magnification view (bule frame in A, × 40); D: High magnification view of red frame in B (× 200); E: High magnification view of yellow frame in C (× 200); F: Image showing signet-ring cell carcinoma invasion of station 3 lymph node (N2) (× 40).

Figure 4 Immunochemical staining. Tumor cells positive for mucin (MUC)5AC (A, × 10) and negative for MUC6 with an MUC5AC/MUC6 double layer (B, × 4)and Ki-67 (C, × 4) localization both absent.