Endoscopic Full-thickness Resection for Gastric Tumor

Endoscopic full-thickness resection (EFTR) is a natural orifice transluminal endoscopic surgery (NOTES) that was developed to overcome the limitations of laparoscopic resection and conventional endoscopic resection methods (endoscopic mucosal resection and endoscopic submucosal dissection). EFTR can be performed with endoscopy only or combined with a laparoscopic approach. During EFTR, the lesions can be exposed to peritoneum or not. Laparoscopic and endoscopic cooperative surgery (LECS) is a well-known procedure in which the lesion is exposed to peritoneum. Non-exposed endoscopic wall-inversion surgery (NEWS) and simple non-exposure EFTR were developed to escape the exposure of the lesions to peritoneum. Submucosal tunneling method may be a good candidate for treatment of subepithelial tumors at the esophagogasric junction and gastric cardia. This review will give an overview about current EFTR techniques to treat subepithelial tumors and adenocarcinoma of stomach.

Diagnosis of Gastric Subepithelial Tumor: Focusing on Endoscopic or Radiologic Approach

Subepithelial tumors (SETs) are occasionally found in the esophagus and stomach during upper endoscopy. Most SETs are asymptomatic and therefore clinically insignificant. However, SETs do have malignant potential, and therefore it is important to distinguish malignant from benign lesions. Among gastric SETs, gastrointestinal stromal cell tumors (GISTs) have malignant potentials that are related to tumor size; however, malignancy can occasionally be found in smaller lesions. Endoscopic ultrasound (EUS) can be used to diagnose GISTs preoperatively, although differential diagnosis on the basis of imaging alone is insufficient. However, when used in combination with EUS-guided fine needle aspiration, diagnostic accuracy increases, although the results can be quite variable. Therefore, we performed endoscopic biopsy of gastric SETs using the endoscopic submucosal dissection (ESD) technique. Our data indicate that deep biopsy via ESD is a safe modality of high diagnostic yield compared with EUS-guided fine needle aspiration in determining the histopathologic features of upper gastrointestinal (GI) SETs, relatively. In addition, pathologic confirmation can be more important than EUS finding. Diagnostic results improve clinical decision making on managing upper GI SETs. It can be recommended that this modality should be considered in upper GI SETs before determining whether tumors should undergo long-term monitoring or surgical resection.

Extragastrointestinal Stromal Tumor Mimicking Gastric Subepithelial Tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract; however, it also occurs at a lower frequency in extra-gastrointestinal regions, such as omentum, mesentery, retroperitoneum, and undefined abdominal sites. This tumor is called an extragastrointestinal stromal tumor (EGIST). A 53-year-old woman presented with a gastric subepithelial tumor, which was incidentally detected by gastrofiberscopy. Contrast abdominal computed tomography (CT) showed a well-defined exophytic tumor with a minimally delayed peripheral enhancing nature near the gastrohepatic ligament. Surgical intervention was indicated, and laparoscopic surgery was planned. During surgery, no specific abnormality was found in the gastric wall and there was no evidence of a gastric subepithelial tumor. Based on immunohistochemical results, sensitive and specific immunostaining was observed for c-KIT, DOG-1, and PKC-theta. In this case, the tumor was positive for CD-117(c-kit) and for smooth muscle actin expression.

Extragastrointestinal Stromal Tumor Mimicking Gastric Subepithelial Tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract; however, it also occurs at a lower frequency in extra-gastrointestinal regions, such as omentum, mesentery, retroperitoneum, and undefined abdominal sites. This tumor is called an extragastrointestinal stromal tumor (EGIST). A 53-year-old woman presented with a gastric subepithelial tumor, which was incidentally detected by gastrofiberscopy. Contrast abdominal computed tomography (CT) showed a well-defined exophytic tumor with a minimally delayed peripheral enhancing nature near the gastrohepatic ligament. Surgical intervention was indicated, and laparoscopic surgery was planned. During surgery, no specific abnormality was found in the gastric wall and there was no evidence of a gastric subepithelial tumor. Based on immunohistochemical results, sensitive and specific immunostaining was observed for c-KIT, DOG-1, and PKC-theta. In this case, the tumor was positive for CD-117(c-kit) and for smooth muscle actin expression.