Endoscopic ultrasound-guided drainage of extraluminal colorectal mucocele using a lumen-apposing metal stent: a novel approach

Colorectal mucoceles are rare mucinous cysts arising in the gastrointestinal tract and presenting diagnostic and therapeutic challenges. We report the first successful treatment of an extraluminal colorectal mucocele using a lumen-apposing metal stent (LAMS). A 65-year-old male with a known medical history of diverticulitis treated with a partial colectomy presented with constipation and low back pain. Computed tomography scan (CT) revealed a 5.4 cm cystic structure adjacent to the rectal anastomosis. Endoscopic ultrasound (EUS) found a subepithelial lesion with an “onion peel” appearance, and aspiration cytology confirmed a colo-colonic mucocele. Management consisted of EUS-guided placement of an 8 × 8 mm LAMS, allowing for drainage, irrigation, and suctioning of the cavity. Complete resolution was achieved without recurrence over a 2-year follow-up period. This case demonstrates the potential of advanced endoscopic techniques, particularly LAMS, in managing extraluminal colorectal mucoceles. While further research is needed to compare the efficacy of LAMS with other treatment modalities, this procedure offers a minimally invasive alternative to surgery for certain patients.