Yan-Qin Long, Wen-Li Xu, Lu-Xiu Li, Hui-Qin He, Jing-Jie Wang, Guo-Dong Shan, Ning Dai, and Hong-Tan Chen. J Neurogastroenterol Motil 2024;30:184-93. https://doi.org/10.5056/jnm23084

A 16-year-old girl, a high school student, presented with a 2-year history of intermittent pain in the left upper abdomen. Routine laboratory tests performed at the time of admission were normal. Contrast-enhanced abdominal computed tomography revealed an intussusception-like appearance at the duodenojejunal junction ([Fig. 1]). The patient underwent small bowel enteroscopy without balloon assistance, which revealed a large submucosal lesion at the duodenojejunal junction, measuring approximately 5 × 3 cm. The lesion had a smooth mucosal surface with a depressed area on the oral side ([Fig. 2], [Video 1]). Surgical resection was subsequently performed. Intraoperatively, a soft, mobile mass located near the ligament of Treitz in the jejunum was excised for pathological examination. Pathological analysis showed ectopic gastric mucosa, including gastric pits and fundic glands, within normal small intestinal mucosa, with mature cellular differentiation. Additionally, a duplicated segment of the digestive tract lined by gastric mucosa and pseudostratified ciliated columnar epithelium, surrounded by a complete muscularis mucosae, was identified ([Fig. 3]). A final diagnosis of small bowel duplication was established. Postoperatively, the patient experienced no recurrence of abdominal pain. Gastrointestinal duplications are rare congenital anomalies, usually found in children, with a higher incidence in boys, typically within the first 2 years of life [1] [2]. Approximately 2–12% of small bowel duplications occur in the duodenum, 44% in the ileum, and 50% in the jejunum [3]. The clinical presentation depends on the duplication size and epithelial type. Duplications lined with gastric epithelium can secrete acid, leading to ulceration, gastrointestinal bleeding, or acute abdomen in cases of perforation. Other symptoms may include chronic abdominal pain, nausea, vomiting, jaundice, pancreatitis, and an abdominal mass [4] [5]. Preoperative diagnosis remains challenging; however, advancements in small bowel enteroscopy allow for precise detection. In this case, enteroscopy provided a clear and comprehensive view of the jejunal lesion. This case will assist endoscopists in promptly diagnosing this condition in the future. Endoscopy_UCTN_Code_CCL_1AB_2AZ_3AZ Article published online: 14 January 2025 © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

We report the case of a 60-year-old Chinese woman admitted to the hospital presenting with persistent vomiting and abdominal pain for one month. She had a history of endometrial cancer treated with surgery two years ago followed by serplulimab (a PD-1 inhibitor) therapy. Initial gastroscopy at a local clinic showed no abnormalities, which prompted a referral to our institution. Upon admission, a diagnostic gastroscopy revealed extensive gastric exfoliative changes without involvement of the esophagus or duodenum, and a nasojejunal tube was placed for nutritional support ([Video 1], [Fig. 1]). Serological and pathological testing further confirmed a cytomegalovirus infection in the gastric mucosa ([Fig. 2]). Treatment was therefore initiated with methylprednisolone (80 mg intravenous injection daily) and ganciclovir (0.5 g orally three times daily) with clinical improvement. Since immune checkpoint inhibitors have significantly transformed the therapeutic landscape of malignancies [1], immune-related adverse events have emerged as a concomitant challenge that can involve multiple organ systems [2]. This case describes a rare manifestation of a PD-1 inhibitor-related gastritis complicated by a cytomegalovirus infection, which was characterized by isolated gastric mucosal damage in the gastrointestinal tract. The combination of steroid and antiviral therapy proved to be effective in managing this condition. Interestingly, although the interval between the gastroscopy performed at our hospital and the one conducted at the local clinic was less than one month, the results differed significantly, even though the patient had undergone immune checkpoint inhibitor therapy for nearly two years. In addition, we provide detailed imaging and video documentation to support recognition by endoscopists and clinicians. Endoscopy_UCTN_Code_CCL_1AB_2AC_3AZ Article published online: 01 August 2025 © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany