LAUSR

A 57-year-old woman presented with intermittent abdominal pain of 5 months’ duration. Physical examination and laboratory tests were normal. Esophagogastroduodenoscopy showed a submucosal tumor (SMT) originating from the lower esophagus (▶Fig. 1). Endoscopic ultrasound (EUS) demonstrated a hypoechoic, homogeneous tumor (27mm× 21mm) with a regular margin arising from the muscularis propria (▶Fig. 2). Submucosal tunneling endoscopic resection (STER) was performed. After the tumor was revealed, an injection needle was used to pierce the tumor to prevent additional injury to the aorta: a goldenyellow liquid flowed out. A 10-mL sample of this liquid was taken for testing, and total bilirubin was found to be 146.3μmol/L. An esophageal biloma was suspected. To avoid infection due to rupture of the biloma, we stopped the procedure. After hemostasis with hot biopsy forceps in the tunnel, several clips were used to close the mucosal defect (▶Video 1). Subhepatic bile collections (bilomas) are usually caused by postoperative biliary injury in the liver or gallbladder fossa [1]; idiopathic bilomas are rare. In this paper, we report for the first time a rare case of a biloma mimicking a SMT arising from the lower esophagus in a patient with no history of surgery, abdominal trauma, liver disease, or biliary disease. Because it is hard, on the endoscopic view within the tunnel, to distinguish tumors from physiologic protrusions (especially the aorta) and from the normal muscular layer [2], during STER in our endoscopy center an injection needle was used to pierce the tumor in order to prevent additional injury to the aorta. Hence, a biloma was identified and potential rupture of the tumor during STER was avoided. Although EUS is widely recognized for evaluating a SMT [3, 4], we still consider that use of an injection needle is necessary to confirm the identity of a SMT during STER.