Abstract
BACKGROUND: Abscess formation is one of the complications after radical resection of rectal cancer; cases with delayed postoperative anastomotic abscess are rare. Here, we report a rare case of postoperative anastomotic abscess with a submucosal neoplasm appearing after rectal surgery. Ultimately, the patient was diagnosed and treated by endoscopic fenestration. In addition, we review the literature on the appearance of an abscess as a complication after rectal cancer surgery. CASE SUMMARY: A 57-year-old man with a history of rectal malignancy resection complained of a smooth protuberance near the anastomotic stoma. Endoscopic ultrasonography revealed a hypoechoic structure originating from the muscularis propria, and a submucosal tumor was suspected. The patient was subsequently referred to our hospital and underwent pelvic contrast-enhanced computed tomography, which revealed no thickening or strengthening of the anastomotic wall. In order to clarify the origin of the lesion and obtain the pathology, endoscopic fenestration was performed. After endoscopic procedure, a definitive diagnosis of delayed anastomotic submucosal abscess was established. The patient achieved good recovery and prognosis after the complete clearance of abscess. CONCLUSION: Endoscopic fenestration may be safe and effective for the diagnosis/treatment of delayed intestinal smooth protuberance after rectal cancer surgery.