Intraabdominal abscess mimicking gastric cancer recurrence: a case report.

Surgical site infection is a common healthcare-associated infection that rarely occurs several months after surgery. Herein, a case is described in which an abdominal mass lesion was found at a 6-month follow-up visit after gastrectomy was performed for early gastric cancer. Positron emission tomography-computed tomography revealed a 2.5 cm-sized mass with a high maximal standard uptake value (8.32), located above a previous anastomosis site. Locoregional recurrence of gastric cancer was diagnosed by multidisciplinary team discussion, and explorative laparotomy was performed. However, surgical and pathologic findings revealed that the mass was an intraabdominal abscess. In conclusion, differential diagnosis of delayed abscess formation should be considered if the possibility of tumor recurrence is low, especially after early gastric cancer surgery.