Fig. 4
a Macroscopically total gastrectomy specimen showed a 0–IIc lesion measuring 34 × 50 mm and a submucosal tumor measuring 65 × 92 mm. b Contents of the cystic lesion were a papillary tumor constituting the cyst wall, necrotic tissue, and a large amount of coagula. c, d Histopathologically a 0–IIc lesion showed shallow infiltration to muscularis propria by well-differentiated adenocarcinoma (hematoxylin and eosin stain, magnification ×20). e Papillary tumor was composed of spindle-shaped cells with oval nuclei (hematoxylin and eosin stain, magnification ×20). f, g Immunohistochemical studies indicated strong staining for CD34 (f) and CD117(c-KIT) (g) (magnification ×20)