Right kidney contusion following endoscopic mucosal resection of hepatic flexure lymphangioma: a rare case report.

Endoscopic mucosal resection (EMR) is widely utilized for the removal of benign colonic lesions; nevertheless, it carries certain inherent risks. We present a rare case of right kidney contusion following EMR for hepatic flexure lymphangioma, representing an uncommon and underreported complication. A 50-year-old woman underwent colonoscopy, which identified a 3 cm cystic mass at the hepatic flexure, subsequently diagnosed as a lymphangioma. EMR was performed with electrocoagulation and mechanical clamping. Postoperatively, she developed progressively worsening upper abdominal pain but did not present with hematuria or hematochezia. Imaging demonstrated edema of the ascending colon wall, free pericolic gas, a perirenal hematoma, and a hemorrhagic focus in the liver. She was managed conservatively with antibiotics, supportive care, and close monitoring in the intensive care unit. Over the following two weeks, her symptoms improved substantially and she was discharged without sequelae. This case illustrates that rare complications such as renal contusion may occur after EMR, emphasizing the need for vigilant postoperative care and awareness of potential injury to adjacent organs, particularly the kidneys. Timely imaging and a multidisciplinary approach are essential for optimal outcomes.