Fatal submucosal invasive gastric adenosquamous carcinoma detected at surveillance after gastric endoscopic submucosal dissection

Figure 1 Initial early gastric cancer lesion in June 2005. A: 0-IIa type well differentiated adenocarcinoma limited to the mucosa, 10 mm in size, without an ulcer scar, on the lesser curvature of the middle gastric body; B: Histopathological findings revealed a well differentiated mucosal adenocarcinoma, 10 mm in size, without lymphovascular involvement or ulcerative finding, as well as tumor-free margins.

Figure 2 Metachronous early gastric cancer lesion in November 2007. A: 0-IIc type metachronous early gastric cancer lesion, 8 mm in size, without an ulcer scar, on the greater curvature of gastric antrum. The estimated tumor depth was up to the mucosa; B: Biopsy revealed well and poorly differentiated adenocarcinoma (hematoxylin-eosin staining).

Figure 3 Histopathological findings of endoscopic submucosal dissection specimens. A: Low magnification view with hematoxylin and eosin staining. Endoscopic submucosal dissection specimen revealed adenosquamous carcinoma invading the deep submucosal layer (1600 μm); B: High magnification view of yellow box in A. The tumor shows a solid growth pattern and prominent keratinization suggesting squamous cell carcinomatous component.

Figure 4 Immunochemical staining. Immunohistochemical staining was focally positive for CK5/6 (A), CEA (B), CDX2 (C), and a few cells were positive for CK14 (D), P63 (E).

Figure 5 Computerized tomography in January 2008 (two months after the endoscopic submucosal dissection). A and B: Enhanced computerized tomography revealed multiple low density areas suggesting liver metastases (indicated by arrows).