Gastric polyposis

Gastric polyps are discrete intra-intestinal protrusions of mucosal or submucosal tissue. These lesions represent proliferative growths that may contain the potential for malignant transformation. [ 1 ] Gastric polyps have multiple subtypes, the most commonly encountered and described are the triad of gastric hyperplastic polyps (GHPs), characterized by marked foveolar cell hyperplasia, foveal gland polyps (FGPs), characterized by dilated and irregularly distributed gastric glands predominantly covered by positional cells with a smaller proportion of chief cells, and adenomatous polyps, characterized by low-grade dysplasia of glandular cells. [ 2 ], [ 3 ], [ 4 ]

However, the group of gastric polyps also includes a much broader differentiation of lesions, including carcinoids (groupings of endocrine cells resulting in a protruding mass), infiltrative lesions (xanthomas, lymphoid proliferations), mesenchymal proliferations (gastrointestinal tumors, leiomyoma, fibrous polyps), and hamartomatous lesions (Peutz-Jager, Cowden, juvenile), all of which can cause a mucosal/submucosal protrusion presenting as a gastric polyp. It is difficult to recognize the likely histopathology of a polyp simply by endoscopy; in most cases, biopsy and histopathologic evaluation are necessary to guide treatment.

Epidemiology

The prevalence and distribution of gastric polyps varies widely depending on the source, but according to a review of several well-powered studies, the prevalence of gastric polyps in patients undergoing endoscopy ranged from 2% to 6%.[ 5 ] Of these, GHPs account for 17% to 42%, FGPs account for 37% to 77%, adenomas account for 0.5% to 1%, and malignancies account for approximately 1% to 2%.[ 6 ] Gastric polyps are most commonly found at the fundus, and their prevalence increases with age. The gender distribution in the literature varies widely. However, FGPs are more common in women and adenomas in men. Differences in diet and lifestyle in different populations contribute to the large differences reported in different studies.[ 7 ]

Causes gastric polyp

The vast majority of gastric polyps are discovered by chance during endoscopic examination or autopsy, so the cause of their formation is not well understood.

The development of gastric hyperplastic polyps is thought to be related to chronic inflammation, usually associated with H. pylori infection and atrophic gastritis. The association with H. pylori is due to the fact that in many cases (70%), gastric hyperplastic polyps regress within a year after eradication of H. pylori infection, provided that reinfection does not occur. Less is known about the causes of gastric polyps. However, several studies have shown an association with chronic use of proton pump inhibitors, suggesting that their development may be mediated by a mechanism involving suppression of gastric acidity.

The most commonly associated risks for the development of adenoma include age and chronic inflammation/irritation of the affected tissue, leading to intestinal metaplasia and subsequent risk of malignant transformation, usually associated with acquired mutations involving the expression of p53 and Ki-67 genes. It is worth noting here that the detection of gastric adenoma in a young patient may indicate the presence of a more serious genetic disorder, familial adenomatous polyposis (FAP), which deserves further investigation. [ 8 ], [ 9 ]

Symptoms gastric polyp

The vast majority of gastric polyps are asymptomatic, with over 90% of them being discovered incidentally during endoscopy. The most common complaints associated with the detection of gastric polyps are dyspepsia, acid reflux, heartburn, abdominal pain, early satiety, gastric outlet obstruction, gastrointestinal bleeding, anemia, fatigue, and iron deficiency. Only rarely can a physical examination help detect gastric polyps, as most are less than 2 cm in size.[ 10 ]

Diagnostics gastric polyp

Because most gastric polyps are asymptomatic or incidentally discovered, evaluation most often begins with complaints of dyspepsia or the discovery of anemia on routine blood tests. Gastric polyps may be seen on noninvasive imaging, such as computed tomography (CT) or magnetic resonance imaging (MRI), but only in the rare case of a very large polyp. The gold standard for diagnosing gastric polyps is esophagogastroduodenoscopy (EGD) performed by an experienced practitioner.

Differential diagnosis

Below are some important differences to consider when diagnosing stomach polyps:

• Hyperplastic polyp of the stomach
• Fundic gland polyp
• Adenoma
• Familial adenomatous polyposis
• Carcinoma
• Carcinoid
• Xanthoma
• Gastrointestinal stromal tumors
• Leiomyoma
• Fibrous polyps
• Peutz-Jegher syndrome
• Cowden syndrome
• Juvenile polyps
• Hemangioma
• Lymphangioma
• Lymphoma
• Neuroma

Treatment gastric polyp

Because it is difficult to discern the underlying histopathology of a gastric polyp based on endoscopic imaging alone, biopsy and en bloc resection are necessary to guide treatment.[ 11 ]

It is well established that the potential for malignancy increases with lesion size, so it is recommended that all lesions larger than 10 mm be removed by endoscopic mucosal resection (EMR). A more conservative approach used by some practitioners involves removing all polyps larger than 5 mm. Prior to any mucosal manipulation, a dose of a proton pump inhibitor (PPI) is administered intravenously to reduce the acidity of the mucosa and improve hemostasis. In many cases, PPI is continued for 4 to 8 weeks after endoscopy with biopsy to promote healing at the biopsy/resection sites. If H. pylori infection is detected on pathology, antibiotic therapy is initiated. When polyps are removed or biopsied, or gastritis is detected, the endoscopist typically performs simultaneous gastric mapping to determine the etiology of the gastritis, including cold forceps mucosal biopsies at multiple sites throughout the stomach.[ 12 ]

Treatment and follow-up after biopsy are determined by the histopathologic findings of the polyps removed during esophagogastroduodenoscopy (EGD). For GHPs removed by EGD without detection of dysplasia, a single repeat EGD after 1 year of follow-up is recommended. If H. pylori is detected in GHP-associated biopsies, a repeat EGD is often performed after 3 to 6 months for repeat biopsy to confirm eradication of the infection and to monitor regression of the gastric polyps. For FGP, if there is a history of chronic PPI use, it is recommended to discontinue the drug if possible and perform a follow-up EGD within 1 year if lesions larger than 5 to 10 mm were detected at the initial EGD and to monitor the response to therapy. The detection of an adenoma on microscopic evaluation of a gastric polyp indicates the need for an EGD within 1 year. In a patient younger than 40 years who has multiple adenomas detected on EGD, an extensive family history and colonoscopy are recommended to exclude FAP. If dysplasia or early adenocarcinoma is detected on microscopic evaluation of a gastric polyp, a repeat EGD is performed 1 year and again 3 years after the initial endoscopy.[ 13 ]

Forecast

In general, the prognosis of gastric polyps is good: some studies indicate the detection of malignancy in less than 2% of polyps examined. Polyp characteristics that indicate a poor prognosis include large size, older age of the patient, and the presence of multiple adenomas. It is known that the risk of detecting dysplasia or malignancy increases significantly with lesions larger than 20 mm in older patients, and that the presence of multiple adenomas may indicate the presence of FAP, which has a high risk of adenocarcinoma.

Sources

1. Park DY, Lauwers GY. Gastric polyps: classification and management. Arch Pathol Lab Med. 2008 Apr;132(4):633-40.
2. Markowski AR, Markowska A, Guzinska-Ustymowicz K. Pathophysiological and clinical aspects of gastric hyperplastic polyps. World J Gastroenterol. 2016 Oct 28;22(40):8883-8891.
3. Carmack SW, Genta RM, Graham DY, Lauwers GY. Management of gastric polyps: a pathology-based guide for gastroenterologists. Nat Rev Gastroenterol Hepatol. 2009 Jun;6(6):331-41.
4. Burt R.W. Gastric fundic gland polyps. Gastroenterology. 2003 Nov;125(5):1462-9.
5. Islam RS, Patel NC, Lam-Himlin D, Nguyen CC. Gastric polyps: a review of clinical, endoscopic, and histopathologic features and management decisions. Gastroenterol Hepatol (NY). 2013 Oct;9(10):640-51.
6. Markowski AR, Guzinska-Ustymowicz K. Gastric hyperplastic polyp with focal cancer. Gastroenterol Rep (Oxf). 2016 May;4(2):158-61.
7. Abraham SC, Singh VK, Yardley JH, Wu TT. Hyperplastic polyps of the stomach: associations with histologic patterns of gastritis and gastric atrophy. Am J Surg Pathol. 2001 Apr;25(4):500.
8. Cao H, Wang B, Zhang Z, Zhang H, Qu R. Distribution trends of gastric polyps: an endoscopy database analysis of 24,121 northern Chinese patients. J Gastroenterol Hepatol. 2012 Jul;27(7):1175-80.
9. Carmack SW, Genta RM, Schuler CM, Saboorian MH. The current spectrum of gastric polyps: a 1-year national study of over 120,000 patients. Am J Gastroenterol. 2009 Jun;104(6):1524-32.
10. Argüello Viúdez L, Córdova H, Uchima H, Sánchez-Montes C, Ginès À, Araujo I, González-Suárez B, Sendino O, Llach J, Fernández-Esparrach G. Gastric polyps: Retrospective analysis of 41,253 upper endoscopies. Gastroenterol Hepatol. 2017 Oct;40(8):507-514.
11. Goddard AF, Badreldin R, Pritchard DM, Walker MM, Warren B, British Society of Gastroenterology. The management of gastric polyps. Gut. 2010 Sep;59(9):1270-6.
12. Sonnenberg A, Genta RM. Prevalence of benign gastric polyps in a large pathology database. Dig Liver Dis. 2015 Feb;47(2):164-9.
13. ASGE Standards of Practice Committee. Evans JA, Chandrasekhara V, Chathadi KV, Decker GA, Early DS, Fisher DA, Foley K, Hwang JH, Jue TL, Lightdale JR, Pasha SF, Sharaf R, Shergill AK, Cash BD, DeWitt JM. The role of endoscopy in the management of premalignant and malignant conditions of the stomach. Gastrointest Endosc. 2015 Jul;82(1):1-8.
14. Ji F, Wang ZW, Ning JW, Wang QY, Chen JY, Li YM. Effect of drug treatment on hyperplastic gastric polyps infected with Helicobacter pylori: a randomized, controlled trial. World J Gastroenterol. 2006 Mar 21;12(11):1770-3.