Rectal Arteriovenous Malformation Mimicking a Submucosal Tumor: Successful Long‐Term Outcome After Transcatheter Arterial Embolization With N‐Butyl‐2‐Cyanoacrylate‐Lipiodol

ABSTRACT Rectal arteriovenous malformations (AVMs) are rare vascular anomalies that pose diagnostic challenges because they may resemble submucosal tumor–like lesions. A 54‐year‐old man presented with recurrent hematochezia, and a colonoscopy revealed a protruding lesion near the dentate line. Contrast‐enhanced computed tomography and angiography confirmed a rectal AVM classified as Cho type IIIb/Yakes type II. Transcatheter arterial embolization with N‐butyl‐2‐cyanoacrylate–Lipiodol (NL) was performed. A rectal ulcer that developed 2 weeks after treatment was successfully managed with topical hydrocortisone. Follow‐up colonoscopy demonstrated progressive lesion regression without recurrence at 3 years. This case underscores that rectal AVMs may mimic submucosal tumors and require a multimodal diagnostic approach. Transcatheter arterial embolization with NL represents an effective therapeutic option.