Colonoscopy has been used for screening and treatment of diseases worldwide. Endoscopic mucosal resection (EMR) has many major complications such as colon perforation and bleeding. However, cases of minor complications have also been reported. Here, we present a case of massive retroperitoneal hematoma, as a minor complication, after colonoscopy.Patient concerns:
A 57-year-old man was admitted to our hospital because of abdominal pain. He had no past medical history relating to his present condition, and he received EMR at another hospital 11 days before his admission. Dynamic computed tomography (CT) was performed, which showed a massive retroperitoneal hematoma near the third portion of the duodenum.Diagnosis:
The patient had a superior mesenteric vein injury after the colonoscopy.Outcomes:
The patient did not complain of nausea or vomiting and was discharged after 43 days.Lessons:
Although massive retroperitoneal hematoma is a minor complication after colonoscopy, it can be life threatening; thus, we need to know more about this complication. Dynamic CT may be useful in detecting whether the bleeding occurs from the artery or not.