Inverted Hyperplastic Polyp in Stomach: A Case Report and Literature Review / 대한소화기학회지

An inverted hyperplastic polyp (IHP) found in stomach is rare and characterized by downward growth of hyperplastic mucosal component into the submucosa. Because of such characteristic, IHP can be misdiagnosed as subepithelial tumor or malignant tumor. In fact, adenocarcinoma was reported to have coexisted with gastric IHP in several previous reports. Because only 18 cases on gastric IHP have been reported in English and Korean literature until now, pathogenesis and clinical features of gastric IHP and correlation with adenocarcinoma have not been clearly established. Herein, we report a case of gastric IHP which was initially misdiagnosed as gastrointestinal stromal tumor and resected using endoscopic submucosal dissection. Literature review of previously published case reports on gastric IHP is also presented.

A Case of Gastric Inverted Hyperplastic Polyp Found with Gastritis Cystica Profunda and Early Gastric Cancer

A gastric inverted hyperplastic polyp is a rare type of gastric polyp and is characterized by downward growth of a variety of mucosal components into the submucosa. The polyp consists of columnar cells resembling foveolar epithelium and pyloric gland epithelium and can coexist with gastritis cystica profunda. Frequently, adenocarcinoma can coexist, but the relation is not clear. A 77-year-old male underwent endoscopic submucosal dissection due to early gastric cancer. A gastric inverted hyperplastic polyp was found in the removed specimen and gastric cystica profunda was also found. We report a case of gastric inverted hyperplastic polyp coexisting with gastric cystica profunda and gastric adenocarcinoma.

Multifocal Adenocarcinomas Arising within a Gastric Inverted Hyperplastic Polyp

We present herein the occurrence of multifocal adenocarcinomas with a minute signet ring cell carcinoma that arose within a gastric inverted hyperplastic polyp (IHP) in a 40-year-old woman. Endoscopic ultrasonography demonstrated a heterogeneous hypoechoic mass in the third layer of the gastric wall. The endoscopic submucosal dissection specimen measuring 3.5x3.2x1.8 cm was a well-circumscribed protruding lesion that had a slit-shaped cavity. Histologically, the lesion consisted mainly of endophytic proliferation of hyperplastic columnar cells resembling normal foveolar epithelium. In addition, six foci of adenocarcinomas and a minute focus of signet ring cell carcinoma were randomly distributed in the superficial and deep regions. The adenocarcinoma was gradually transitioning from dysplasia, while the signet ring cell carcinoma was surrounded by hyperplastic foveolar epithelium. This is the first report of a gastric IHP with multifocal intramucosal adenocarcinomas and a signet ring cell carcinoma, and endoscopic submucosal dissection is used to completely resect it.

A Case of Gastric Inverted Hyperplastic Polyp Associated with Gastritis Cystica Profunda and Early Gastric Carcinoma

A gastric inverted hyperplastic polyp is characterized by downward growth of the hyperplastic mucosal components into the submucosa. Lesions are composed of hyperplastic foveolar-type glands, and sometimes coexist with gastritis cystica profunda (GCP). Adenocarcinoma frequen- tly can coexist, but the relationship is not clear. A 71-year-old male was admitted to hospital because of dyspepsia for one month. He underwent a wedge resection of the stomach, after endoscopic biopsies. The gross finding showed a slightly elevated papillary lesion with central depression. Microscopically, the elevated lesion was composed of hyperplastic fundic glands and foveolar cells, and the central depressed lesion showed a nodular inverted proliferation of normal appearing gastric epithelium and glands in the submucosa. An additional proximal gastrectomy specimen exhibited marked GCP and a minute adenocarcinoma at the proximal margin with p53 protein overexpression.