A 36-year-old woman presented with epigastric pain and anemia. Gastrointestinal endoscopy revealed an elevated mucosal lesion with linear ulceration in the anterior wall of the gastric antrum, located very close to the pylorus (Fig. 1a). A definitive diagnosis could not be obtained, even with an incisional biopsy. She was referred to our hospital for further investigation and treatment.
The patient’s medical history and family history were noncontributory. Laboratory evaluation, including tumor marker levels, showed results within the normal range except for the presence of anemia. Endoscopic ultrasonography showed a heterogeneous echoic tumor in the submucosal layer not involving the muscularis propria (Fig. 1b). Computed tomography (CT) showed a nodular soft tissue mass in the gastric antrum, with no apparent metastatic lesions. There was no significant uptake of 18F-fluorodeoxyglucose into the tumor on a positron emission tomography/CT scan (Fig. 1c, d).
The results were inconclusive for excluding malignant potential of the tumor. Additionally, resection with ESD technique was difficult to perform, given the high risk of perforation during the procedure. Under the presumption that the tumor was a GIST, schwannoma, or other types of submucosal tumors, we sought to achieve a definitive diagnosis by radical resection for total biopsy with minimal margins. Among the various surgical procedures, we chose LECS, with more than usual caution on the prevention of gastric juice leakage into the intraperitoneal cavity (Fig. 2a, b). LECS was performed as described by Hiki et al. [1]. Briefly, it is executed in three main parts. First, the endoscopist marks the smallest negative margin around the tumor using the ESD technique. Second, the submucosal incision is extended toward the serosa passing through the muscularis propria, resulting in a small artificial perforation. Finally, a surgeon resects the tumor laparoscopically with the guidance of the endoscope and surgical marks. The defect in the gastric wall is then closed either with the continuous hand-sewn technique or using linear staples. We chose the continuous hand-sewn technique, because a portion of the suture line was on the pylorus.
The resected specimen appeared as a gray white solid tumor, measuring 25 × 22 × 20 mm (Fig. 3a, b), with negative margins. The tumor was located in the lamina propria mucosae and protruded into the muscularis propria, showing no necrosis or lymphovascular invasion. Histopathological examination revealed partial dense collagenous matrices and networks of fine capillary-caliber blood vessels, showing infiltration of lymphocytes, plasma cells, and mast cells. The tumor demonstrated lobular or fused nodular growth of spindle cells without atypical cytology, with abundant alcian blue-positive myxoid extracellular matrix (Fig. 3c, d).
After the confirmation of the diagnosis and the decision that additional treatments were unnecessary, the patient was discharged on postoperative day 8 with no complications, such as delayed gastric emptying or outlet obstruction. She has been followed in the outpatient clinic and shown no signs of recurrence or metastasis. No distortion of the stomach was evident on endoscopy (Fig. 4).
