Recently, the proportion of H. pylori-positive patients has gradually decreased due to the widespread use of H. pylori eradication therapy; consequently, the incidence of H.pylori-uninfected gastric epithelial neoplasms (HpUGENs) has been gradually increasing in East Asia. Among these HpUGENs, gastric foveolar-type adenoma with a raspberry-like appearance (GFA-R), which presents as a strongly reddish, nodular or granular elevated lesion, represents one of the lesions most frequently encountered in routine clinical practice and has garnered increasing attention. In the latest WHO classification, it has been newly defined as a foveolar-type adenoma. Although its current prevalence in Western countries appears to be relatively low, it is expected to become a clinically significant entity in these regions in the foreseeable future. However, endoscopic treatment strategy for GFA-R has not yet been established. We aimed to clarify the efficacy and safety of endoscopic procedures (cold forceps polypectomy (CFP), cold snare polypectomy (CSP), and endoscopic mucosal resection (EMR)) for GFA-R.

We retrospectively analyzed 88 raspberry-like lesions in 74 patients that were endoscopically treated at our institution between January 2009 and December 2023 and were pathologically diagnosed as foveolar-type adenoma in accordance with the WHO classification. The clinicopathological characteristics , endoscopic characteristics, and treatment outcomes of GFA-R were evaluated retrospectively.

The median age was 56 years (range, 29–85 years), and the male to female ratio was 49:25. Proton pump inhibitor or potassium-competitive acid blocker use was observed in 16 of 74 patients (21.6%), smoking history in 32/74 (43.2%), and alcohol history in 30/74 (40.5%). Regarding the lesion location, GFA-Rs occurred mostly in the greater curvature of the upper and middle third of the stomach. The median tumor size was 4.0 mm (range, 1–10 mm). Endoscopic procedures consisted of biopsy alone (n = 6), CFP; n = 42, outpatient/inpatient: 38/4, CSP; n = 4, 1/3, and EMR; n = 36, 0/36. The overall en bloc resection rate was 94.3% (83/88): 90.4% in CFP (38/42), 75.0% in CSP (3/4), and 97.2% in EMR (35/36). Lesions smaller than 5 mm were mainly treated with CFP (34/58), whereas lesions ≥5 mm were mainly treated with EMR (20/30). Histologically, all lesions were intramucosal neoplasms without lymphovascular invasion. The curative resection rate was 97.7% (86/88). In two lesions, the horizontal and vertical margins were histologically indeterminate; however, no residual tumor was detected endoscopically. No intraoperative or delayed complications, such as bleeding or perforation, occurred with any procedure. The mean follow-up period after treatment was 28.7 months (range, 2–165 months), and no local recurrences were observed endoscopically at 1 year (n = 62), 2 years (n = 40), or 3 years (n = 24) after endoscopic treatment, including in cases with piecemeal resection or indeterminate margins.

In this series of 88 GFA-R lesions, the efficacy and safety of endoscopic procedures for GFA-R may be confirmed regardless of procedure method. Moreover, outpatient CFP might have proven to be a simple, useful, and economical endoscopic procedure for GFA-R of smaller than 5 mm.