A Case of Gastric Neuroendocrine Tumor With a Raspberry‐Like Appearance on the Background of Acid‐Suppressive Therapy‐Related Gastropathy

We report the case of a 52-year old man who was referred to our institution after a routine health check identified an asymptomatic gastric polyp. The medical history of the patient included reflux esophagitis, for which he had been treated with vonoprazan 10 mg daily for 6 years after initially receiving proton pump inhibitors. Endoscopy revealed a 4-mm, hemispherical, uniformly reddish Yamada type II lesion on the anterior wall of the gastric body, arising from nonatrophic mucosa with multiple small hyperplastic polyps. Magnifying narrow-band imaging revealed a regular microvascular and microsurface pattern, producing a raspberry-like appearance. Histological examination of the biopsy specimen revealed a grade 1 neuroendocrine tumor. Contrast-enhanced computed tomography revealed no evidence of metastatic lesions. En bloc resection was successfully performed using endoscopic submucosal dissection. Pathological examination confirmed a 5-mm grade 1 neuroendocrine tumor with negative margins and no vascular invasion. Gastric neuroendocrine tumors with raspberry-like morphology are rare. This case underscores the importance of considering gastric neuroendocrine tumors in the differential diagnosis of raspberry-like gastric lesions, particularly in patients with potent acid-suppressive therapy-related gastropathy. <b>Trial Registration</b>: N/A.