An Iranian 40-year-old lady was referred to the gastroenterology department of Taleghani Hospital with a submucosal mass lesion. The patient described her symptoms as intermittent epigastric pain, discomfort, dyspepsia, and heartburn from more than six months before the admission. No significant weight loss was detected in our case. She revealed two caesarean sections as the past medical history and the family history of gastrointestinal malignant disorders was negative. In addition, she denied any positive history of alcohol drinking or smoking.
On physical examination, her temperature was 37.6 C, heart rate was about 84 beat per minute, and blood pressure was 110/70 mm-Hg. Abdominal examination showed a soft and non-tender abdomen with no sign of organomegally or palpable mass. The rest of the physical examinations and laboratory tests were normal.
The evaluations before the referral included upper and lower GI tract endoscopy and ultrasonography. Endoscopy reported a polyp-like lesion in the antrum, while the mucosa in this place was normal. In addition, EUS showed a 16.3 mm subepithelial, iso-hyperechoic lesion originating from the submucosal layer. The pillow sign of the mass was negative. The gross feature of the lesion was in favor of lipoma.
 Endoscopic devices and procedures 
A soft, straight, transport cap with an inside rim (D-201-11802, Olympus) was fitted on to the tip of a standard single channel endoscope (GIF-260, Olympus). Other devices included Needle Knife (Olympus), Hot snares, and Hemoclips (Micro-Tech Nanjing Co., Ltd.).
Under sedation with intravenous propofol in standard position, endoscopy was performed. The procedures included the following steps and all of them were attended by an expert and single endoscopist (Figure 1). 
 The submucosal lesion was detected by retroflexed maneuver. Then, after the estimation the site of the polyps. The mucosal surface was unroofed with needle knife (this part is different with other previous known methods.). The lesion was retracted with grasps, and the mass was enucleated. It was resected with standard polypectomy hot snares. After resection, the mass was sent to a pathologist. Two hemoclips for each mass were inserted on the base of the lesion (Figure 1). Follow-up assessment
In both cases, second look endoscopy was performed after six hours of the resection. The outcomes were followed up by endoscopy after the two months following the procedure, to confirm the healing of the artificial ulcers and other complications. The assessment of endoscopic parameters included resection rate, early and delayed perforation rate, early and delayed bleeding rate, dehiscence rate, and recurrence rate.
 Histopathological examinations 
In both cases, the tissue specimens were fixed in formalin solution. The histological analysis included the identification of cell types, nuclear atypia, histopathological type, tumor size, and tumor invasion. In the first case, immunohistochemical study was also performed. Furthermore, the margins of resection were examined macroscopically and microscopically.
 Histopathological results 
 Case 1  
The specimen consisted of a polypoid creamy tissue fragment measuring 1.7x1.5x1 cm and tiny fragments of creamy soft tissue measuring 1x0.7x0.3 cm. \4The primary histopathological analysis suggested gastrointestinal stromal tumor (GIST). IHC study included Smooth Muscle Antibody (SMA), Desmin, CD117, and DOG1. Desmin and SMA were positive but CD117 and DOG1 were negative. IHC and histologic findings were in in line with leiomyoma.
 Case 2 
The specimen consisted of adipose tissue fragment measuring 1x1x0.5 cm. Histologic findings of endoscopic biopsy confirmed lipoma.
 Follow up 
Re-endoscopy, after six hours of resection reported no early complication, in both cases. After 12 hours of the procedures, both patients were discharged. Once discharged, the patients were prescribed daily oral Proton pump inhibitors (PPI) for two months. After two months, patients were evaluated by endoscopy again. Repeated endoscopy revealed, the hemoclips were spontaneously removed and the mucosa of the antrum was normal, in both cases. No macroscopic evidence of tumor was detected. Furthermore, the resection margins of the polyp were evaluated microscopically. Microscopically, all margins were free. Delayed perforation or delayed bleeding were not detected after 2 months.