Poorly differentiated adenocarcinoma in a gastric hyperplastic polyp

Malignant transformation of a gastric hyperplastic polyp in a context of Helicobacter pylori-negative autoimmune gastritis: a case report

BACKGROUND

Gastric foveolar hyperplastic polyps (GFHPs) are common findings in clinical practice. GFHPs commonly arise in a background of chronic atrophic gastritis, including autoimmune gastritis (type A gastritis), and have a potential risk of malignant transformation.

CASE PRESENTATION

In 2005, a 55-year-old Japanese woman underwent upper endoscopy at another hospital and was found to have a pedunculated polyp (10 mm in diameter) on the greater curvature of the lower gastric body. On biopsy, the polyp was diagnosed as a GFHP. Nine years later, the polyp had grown to 20 mm in diameter, and the biopsy specimen taken at this time showed tubular adenocarcinoma. On admission to our hospital, the serum Helicobacter Pylori (H. pylori) immunoglobulin G antibody and stool H. pylori antigen were both negative. Anti-gastric parietal cell antibody was positive, as was the anti-intrinsic factor antibody, and the fasting serum gastrin level was markedly increased. In 2014, en bloc resection of the pedunculated polyp was performed by endoscopic submucosal dissection. The final histological diagnosis was adenocarcinoma of the stomach with submucosal and lymphatic invasion. Subsequently, additional radical distal gastrectomy was performed. At the latest follow-up (12 months postoperatively), no recurrence was noted.

CONCLUSIONS

We here reported a rare case of malignant transformation of GFHP arising in a context of type A gastritis. To our knowledge, there are no previous reports on malignant transformation of GFHP with submucosal and lymphatic invasion arising in a background of type A gastritis in the English literature. Further, there is currently no effective treatment other than endoscopic or surgical treatment for such cases. Given the potential risk of malignant transformation due to hypergastrinemia, we consider that endoscopic treatment should be considered as a first-line therapy when a malignant growth is suspected.

The clinicopathological features of gastric hyperplastic polyps with neoplastic transformations: a suggestion of indication for endoscopic polypectomy

Background/Aims

Although gastric hyperplastic polyps are usually considered as benign lesions, a low risk of carcinomatous conversion is currently recognized. We aimed to identify the characteristics of hyperplastic polyps undergoing neoplastic transformation.

Methods

A total of 269 gastric hyperplastic polyps from 216 patients removed by endoscopic polypectomy (EP) or surgical resection were enrolled in this study, and their endoscopic pictures and pathology slides were reviewed.

Results

Neoplastic transformation was detected on forceps biopsy specimen in 11 cases. However, the pathology findings from the EP or surgical specimen revealed neoplastic transformation in 14 cases (5.2%; 4 with dysplasia and 10 with adenocarcinoma). No significant difference was found between hyperplastic polyps with and without neoplastic transformation in age, sex, location, number of polyps or gross appearance. However, neoplastic transformations were more frequently found in gastric hyperplastic polyps >1 cm than in polyps ≤1 cm (12 of 143; 8.4% vs. 2 of 126; 1.6%) (p=0.013).

Conclusions

Neoplastic transformations were more frequently found in gastric hyperplastic polyps >1 cm. Therefore, EP should be considered for gastric hyperplastic polyps >1 cm for the accurate diagnosis and definitive treatment.

Papillary adenocarcinoma occurring in a gastric hyperplastic polyp observed by magnifying endoscopy and treated with endoscopic mucosal resection

The patient was a 75-year-old man. He had been diagnosed with gastric hyperplastic polyp 4 years previously. The color of the apex of this polyp was whitish. Magnifying endoscopy findings revealed disappearance of the mucosal microstructure with irregular branched capillaries at the top of the polyp. Endoscopic mucosal resection (EMR) was performed. Histological examination revealed that a part of the polyp surface was replaced with papillary adenocarcinoma. Diagnosis of papillary adenocarcinoma in a hyperplastic polyp with mucosal invasion was made. Magnifying endoscopy was useful for the detection of gastric cancer occurring in the hyperplastic polyp in the present case.

Minute signet ring cell carcinoma occurring in gastric hyperplastic polyp

We describe a 45-year-old woman with minute signet ring cell carcinoma occurring in a gastric hyperplastic polyp. A biopsy specimen obtained from the gastric hyperplastic polyp revealed signet ring cell carcinoma. Endoscopic mucosal resection (EMR) was performed to confirm the diagnosis. Histological examination of the EMR specimen revealed focal signet ring cell carcinoma in the hyperplastic polyp. There are few cases of gastric hyperplastic polyp associated with signet ring cell carcinoma.

Acquired hyperplastic gastric polyps in solid organ transplant patients

OBJECTIVE

We report a series of patients who developed hyperplastic gastric polyps after solid organ transplantation.

METHODS

A retrospective review of patients with solid organ transplantation from January 1997 to December 1999 was performed. Patients with gastric polyps found during endoscopy were included. Demographic data, polyp characteristics (endoscopic and histological), time of endoscopy, and treatment regimens were analyzed.

RESULTS

A total of 10 (seven men, three women) transplanted patients (six cardiac, three liver, and one kidney) with gastric polyps were identified. The median age was 61 yr (27-71 yr), and median time of endoscopy after transplantation was 11 months (3-28 months). Eight patients had endoscopy before or soon after transplantation, with no evidence of polyps. Nine patients had multiple polyps (three or more), and one had a single pedunculated polyp. Polyps were confined to the antrum in eight patients, antrum and body in one patient, and fundus in one patient. All polyps biopsied were found to be hyperplastic and without adenomatous or malignant changes. Cytomegalovirus serology was negative in nine patients. Each patient received standard immunosuppression that included a calcineurin inhibitor and steroids. Steroids were tapered and stopped by 3 months. Azathioprine was added in five patients and mycophenolate mofetil in one patient.

CONCLUSIONS

The development of gastric polyps after organ transplantation has not been previously reported. The development of these gastric polyps (hyperplastic and multiple) is concerning as a malignant potential has been recognized in patients harboring multiple hyperplastic gastric polyps. The exact cause of these polyps is unknown. The association with immunosuppressive therapy as well as the natural history of these acquired hyperplastic gastric polyps needs further investigation.

Hyperplastic polyps of the stomach: associations with histologic patterns of gastritis and gastric atrophy

Hyperplastic polyps are common gastric lesions characterized by hyperplastic foveolae with variable amounts of inflamed stroma. Their pathogenesis is unknown, but they have been reported to occur in association with various forms of chronic gastritis, particularly autoimmune gastritis and Helicobacter pylori gastritis. Comprehensive histologic evaluation of the background mucosal pathology in patients with hyperplastic polyps has not been previously performed. We studied 160 patients with gastric hyperplastic polyps and characterized endoscopic and histologic features of the polyps (i.e., location, multiplicity, and presence of dysplasia and adenocarcinoma) and the background gastric mucosa (i.e., intestinal metaplasia, dysplasia, carcinoma, and presence and classification of gastritis). Hyperplastic polyps were most common in the antrum (60%) and were multiple in 20% of patients. Focal intestinal metaplasia of the polyp was present in 16% and dysplasia in 4% of patients. Only one patient (0.6%) had adenocarcinoma within the polyp. Evaluation of the surrounding gastric mucosa showed at least focal intestinal metaplasia in 37% of patients, adenoma or low-grade flat epithelial dysplasia in 2%, and synchronous or metachronous adenocarcinoma in 6%. Eighty-five percent of patients had inflammatory mucosal pathology, most commonly active chronic H. pylori gastritis (25%), reactive or chemical gastropathy (21%), and metaplastic atrophic gastritis of the autoimmune (12%) or environmental (8%) type. These results indicate a strong association between various forms of gastritis and the development of hyperplastic polyps and further emphasize the importance of biopsy of the nonpolypoid gastric mucosa during endoscopic examination.