Successful treatment of an enormous rectal mucosa-associated lymphoid tissue lymphoma by endoscopic full-thickness resection: A case report

BACKGROUNDColorectal mucosa-associated lymphoid tissue lymphoma (MALToma), a rare kind of nongastric MALToma, lacks consensus on its endoscopic features and standard therapies. According to previous studies on the clinical characteristics and outcomes of colorectal MALToma, endoscopic resection remains a good therapeutic strategy.CASE SUMMARYA 71-year-old woman suffered intermittent hematochezia for 1 mo, accompanied with abdominal pains but without weight loss, fever, chills or fatigue. Colonoscopy showed a massive hemispheric mass with rough and hyperemic mucosa in the lower rectum. Narrow-band imaging magnifying endoscopy detected some branching abnormal blood vessels and disappearance of glandular structure, which was similar with the tree-like appearance sign in gastric MALToma. Endoscopic ultrasonography revealed the lesion to be hypoechoic, boundary-defined, and echo uniform inside, originating from the muscularis propria. Abdominal enhanced computed tomography (CT) demonstrated a soft tissue mass with defined boundary. No enlarged superficial lymph nodes were detected by B-mode ultrasound. C¹³-urea breath test and serum Helicobacter pylori antibody were both negative. The patient underwent endoscopic full-thickness resection. Postoperative pathological analysis indicated colorectal MALToma. The patient remained asymptomatic after discharge, and follow-up positron emission tomography–CT and colonoscopy showed no residual lesion, remnants or lymph node metastasis. CONCLUSIONThis case provides new information on the specific endoscopic features of colorectal MALToma and an alternative treatment for patients.