Gastritis cystica profunda with early gastric cancer persisting for 9 years in the stage of high-grade intraepithelial neoplasia

Abstract

Gastritis cystica profunda (GCP) is a benign lesion characterized by the submucosal proliferation of cystic gastric glands. It most frequently occurs in patients with a history of gastric surgery but is infrequently found in those with an unoperated stomach. While generally benign, GCP has been associated with gastric adenocarcinoma in some cases. We report a case of early gastric cancer (EGC) arising from GCP in a 69-year-old man with no history of gastric surgery. The lesion, which had remained in the stage of high-grade intraepithelial neoplasia for nine years, was successfully treated with endoscopic submucosal dissection (ESD). This case highlights the diagnostic challenges posed by GCP-associated lesions and suggests that such lesions may exhibit an indolent clinical course. In 2016, a gastroscopic examination revealed a 0-IIa + IIc lesion of approximately 40 mm in diameter on the greater curvature of the gastric antrum, close to the posterior wall. A biopsy confirmed high-grade intraepithelial neoplasia. The lesion was deemed indicated for ESD. However, during the procedure, a poor lifting sign following submucosal injection led to the suspicion of submucosal infiltration, and the treatment was subsequently aborted. The patient declined further treatment and opted for clinical follow-up. In 2025, a follow-up gastroscopy showed no significant change in the lesion compared to its 2016 appearance. A second ESD was successfully performed. Histopathological examination of the resected specimen confirmed the diagnosis of GCP with well-differentiated adenocarcinoma (confined to high-grade intraepithelial neoplasia). All lateral and deep margins were free of neoplasia, with no evidence of lymphatic, vascular, or perineural invasion. The surrounding gastric epithelium showed normal mucosa without dysplasia. This case highlights the diagnostic challenges posed by GCP-associated lesions and suggests that, in selected instances, such lesions may follow a relatively indolent clinical course.