Gastric Polyps

Published on 09/08/2015 by admin

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Last modified 22/04/2025

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 Hyperplastic, adenomatous, and hamartomatous

• Fundic gland polyps: Now most common type

image Associated with use of proton pump inhibitor (PPI) medication
image Sometimes considered a variant of hyperplastic polyps
• Hyperplastic polyps

image Virtually no malignant potential
image Typical: Small, multiple, sessile (< 1 cm)
image Location: Fundus and body
• Adenomatous polyps

image Less common (< 20% of benign polyps)
image Increased risk of malignant change
image Usually solitary, > 1 cm
• Hamartomatous polyps

image Peutz-Jeghers syndrome
image Can occur as isolated finding (sporadic)

TOP DIFFERENTIAL DIAGNOSES

• Retained food and pills
• Gastric carcinoma (polypoid type)
• Gastric metastases and lymphoma
• Gastric gastrointestinal stromal tumor
• Ectopic pancreatic tissue

CLINICAL ISSUES

• Prevalence of gastric polyps in patients who have upper endoscopy = 6% (2009 study)
• Fundic (77%), hyperplastic (17%), malignant (2%), adenomas (< 1%)
• Much higher percentage of fundic polyps than in earlier studies

image Caused by increased use of PPI medications
• Syndromic polyps have high association with cancer risk in stomach and other organs

image e.g., familial polyposis, Peutz-Jeghers syndrome
image
(Left) Graphic shows a pedunculated polyp in the gastric antrum, prone to prolapse through the pylorus with peristalsis. Any type of large polyp may prolapse in this fashion, including large hyperplastic, adenomatous, and even polypoid masses arising from the submucosa, such as lipomas.

image
(Right) Upper GI series shows a polypoid mass image in the duodenal bulb that is a prolapsed gastric antral polyp (adenoma).
image
(Left) Film from an upper GI series in a 57-year-old man shows multiple small, sessile polyps image in the gastric body. The appearance and age of the patient are typical for hyperplastic polyps.

image
(Right) Film from an upper GI series of adenomatous polyps in a patient with familial polyposis shows innumerable small polyps throughout the stomach. These are somewhat larger, more numerous, and more irregular in shape than most hyperplastic polyps.

TERMINOLOGY

Definitions

• Protruding, space-occupying lesion within stomach

image Encompass a broad spectrum of conditions that may originate in gastric mucosa or submucosa

IMAGING

General Features

• Best diagnostic clue

image Radiolucent filling defect, ring shadow, or contour defect on barium study
• Morphology

image Hyperplastic polyps: Smooth, sessile

– Fundic gland polyps: Always sessile, multiple, small
image Adenomatous polyps: Usually single with lobulated or cauliflower-like surface
image Hamartomas: Cluster of broad-based polyps
• Other general features

image Polyps classified  based on pathology
image Fundic gland polyps

– Variant of hyperplastic polyps (< 1 cm)
– Have become most common type of gastric polyp
– Associated with use of proton-pump inhibitor medication
image Hyperplastic polyps

– Virtually no malignant potential
– Typical: Small, multiple, sessile (< 1 cm)

image Location: Fundus and body
– Atypical large: Solitary, pedunculated (2-6 cm), location in body and antrum
– Atypical giant: Polyp (6-10 cm) multilobulated mass, location in body and antrum
image Adenomatous polyps

– Less common (< 20% of benign polyps); dysplastic lesions
– Increased risk of malignant change via adenoma-carcinoma sequence
– Usually solitary, occasionally multiple, > 1 cm

image Location: Mostly antrum > body
– Histologically: Tubular (75%), tubulovillous (15%), villous (10%)
– Gastric adenomatous polyps 30x less common than gastric cancer
– Carcinoma in situ and invasive carcinoma: Seen in 50% of adenomatous polyps > 2 cm
– 30-40% associated with atrophic gastritis, pernicious anemia, and cancer
– Higher risk of coexisting gastric cancer than risk of malignant change in polyp
image Polyposis syndromes involving stomach

– Familial adenomatous polyposis (FAP) syndrome 

image > 50% of patients have gastric adenomatous or fundic gland polyps
– Hamartomatous polyposis (e.g., Peutz-Jeghers syndrome [PJS])

image Have increased risk of gastric and other cancers
– Cronkhite-Canada, Cowden, etc.

image All rare but associated with gastric polyps

Fluoroscopic Findings

• Hyperplastic polyps

image Typical: Multiple, smooth, sessile, round or ovoid lesions, < 1 cm in size
image Based on location: Dependent and nondependent wall

– Dependent (posterior wall): Radiolucent filling defects
– Nondependent (anterior wall): Ring shadows and white rim (barium)
image Variant: Fundic gland polyps (multiple, up to 50 in fundus, < 1 cm in size)

– Small rounded nodules, indistinguishable from hyperplastic polyps
image Atypical: Large and giant

– Large: Solitary, conglomerated, pedunculated, lobulated, 2-6 cm in size
– Giant polyps: Multilobulated conglomerate mass with trapping of barium in interstices between lobules; 6-10 cm in size
• Adenomatous polyps

image Usually solitary or rarely multiple, sessile or pedunculated, more lobulated, > 1 cm in size
image Pedunculated polyp en face: Hanging from nondependent anterior wall

– Mexican hat sign: Characterized by pair of concentric rings
– Outer ring: Represents head of polyp
– Inner ring: Represents stalk of polyp
image Lobulated polyp with basal indentation: ↑ risk of adenocarcinoma
image Polyps in antrum tend to prolapse through pylorus

– Cause intermittent gastric outlet obstruction
– Symptoms of transient nausea and vomiting

Imaging Recommendations

• Best imaging tool

image Double-contrast upper GI series

– En face, profile, and oblique views

DIFFERENTIAL DIAGNOSIS

Retained Food and Pills

• Filling defects in barium pool simulating polyps

Gastric Carcinoma (Polypoid Type)

• Lobulated or fungating mass
• Barium study findings

image Dependent or posterior wall: Filling defect
image Nondependent or anterior wall

– Etched in white by thin layer of barium
• Indistinguishable from giant lobulated hyperplastic or adenomatous polyp
• Diagnosis: Endoscopic biopsy and histology

Gastric Metastases and Lymphoma

• Gastric metastases (e.g., malignant melanoma and squamous cell carcinoma)
• Gastric lymphoma (e.g., low-grade mucosa-associated lymphoid tissue [MALT] lymphoma)
• Barium study findings

image Malignant melanoma metastases

– Initially: Submucosal masses seen as filling defects may mimic polyps
– Ulcerated lesions: Bull’s-eye or “target” pattern
image Low-grade MALT lymphoma

– Confluent varying-sized nodules (filling defects)
– May be indistinguishable from gastric FAP syndrome

Gastric GIST

• Submucosal lesion, often with intraluminal and large exophytic component
• Has smooth mucosal surface unless ulcerated
• CT shows more of mass than upper GI series
• Diagnosis: Endoscopic biopsy and histology

Ectopic Pancreatic Tissue

• Location: Greater curvature of distal antrum
• Often contain central umbilication or dimple

image Represents orifice of primitive ductal system

PATHOLOGY

General Features

• Etiology

image Fundic gland polyps

– Have become most common type
– Associated with increased use of proton-pump inhibitors (PPI)
image Chronic atrophic and Helicobacter pylori gastritis
image Hereditary: Autosomal dominant (FAP syndrome and PJS)

– Hamartomatous polyposis syndromes
• Genetics

image FAP syndrome: Abnormal or deletion of APC gene located on chromosome 5q
image Hamartomatous polyposis (PJS)

– Spontaneous gene mutation on chromosome 19
• Associated abnormalities

image Polyposis syndromes

Gross Pathologic & Surgical Features

• Hyperplastic polyps: Small, sessile nodules; smooth, dome-shaped contour
• Fundic gland polyps: Small sessile polyps
• Adenomatous polyps: Tubular (thin stalk and tufted head), sessile (broad base)
• FAP syndrome: Innumerable small to medium-sized polyps
• PJS: Carpet, cluster-like, or scattered polyps

Microscopic Features

• Hyperplastic polyps: Elongated, cystically dilated glandular structures
• Adenomatous polyps: Tubular, tubulovillous, villous pattern; dysplastic cells
• PJS: Muscularis mucosa core extends to lamina propria

CLINICAL ISSUES

Presentation

• Most common signs/symptoms

image Usually asymptomatic
image Ulcerated polyps: Low-grade upper GI bleeding
image FAP syndrome: Rectal bleeding and diarrhea
image PJS: Cramping pain, rectal bleeding, or melena
image Mostly incidental findings on imaging and endoscopy
image Pedunculated polyps in antrum: Nausea and vomiting

– Due to outlet obstruction
• Diagnosis: Endoscopic biopsy and histology

Demographics

• Age

image Hyperplastic polyps: Middle-aged and elderly
image Fundic gland polyps more common in middle-aged women
image FAP syndrome and PJS: 10-30 years
• Gender

image M = F
• Epidemiology

image Incidence

– Gastric polyps: 1-2% of all GI tract polyps
– Prevalence of gastric polyps in patients who have upper endoscopy = 6%  (2009 study)

image Fundic (77%), hyperplastic (17%), malignant (2%), adenomas (< 1%)
image Much higher percentage of fundic polyps than in earlier studies
– FAP syndrome and PJS: 1 in 10,000 people

Natural History & Prognosis

• Complications

image Risk of cancer in adenomatous polyp, FAP syndrome, and PJS
image Gastric outlet obstruction
• Prognosis

image Good: After removal of benign and cancer in situ polyp
image Poor: Invasive carcinoma

Treatment

• Small (< 1 cm) and asymptomatic: Periodic surveillance
• Large (> 1 cm), sessile or pedunculated, and lobulated and symptomatic: Polypectomy

DIAGNOSTIC CHECKLIST

Consider

• Differentiate from other gastric discrete filling defects
• Check for family history of GI tract polyps
• Screen small intestine and colon to rule out associated hereditary polyposis syndromes

image
(Left) Film from an upper GI series in an elderly man with dysphagia shows a well-defined polyp image at the GE junction.
image
(Right) Another spot film from the upper GI in the same patient shows the polyp image prolapsing into the distal esophagus. Endoscopy and resection revealed an adenomatous gastric polyp.
image
(Left) Film from an upper GI series shows a well-defined polyp image in the gastric body.

image
(Right) Endoscopic photograph in the same patient shows an ulcerated mass image that was a benign adenoma. A band was placed around the base of the polyp, and it was resected at endoscopy.
image
(Left) Film from an upper GI series in an elderly man with dyspepsia shows a cluster of polypoid lesions image arising from the gastric cardia and body. These have a smooth surface and most appear sessile.

image
(Right) Upper GI series in the same patient shows that some of the polyps appear to have a stalk image. Endoscopy revealed multiple polyps with a villous adenoma histology.
image
Upper GI series shows a polypoid mass image in the antrum that periodically prolapsed through the pylorus. This case proved to be leiomyoma.

image
Endoscopic photograph shows an antral polyp (adenoma) that intermittently prolapsed through the pylorus image.
image
Upper GI series shows dozens of small hyperplastic gastric polyps.
image
Upper GI series shows multiple hyperplastic gastric polyps.
image
Upper GI series shows a large adenomatous gastric polyp image.
image
Axial CECT shows a large gastric adenomatous polyp image prolapsed into the duodenum.

SELECTED REFERENCES

1. Declich, P, et al. Fundic gland polyps and proton pump inhibitors: an obvious link, or an open question? Hum Pathol. 2014; 45(5):1122–1123.

2. Islam, RS, et al. Gastric polyps: a review of clinical, endoscopic, and histopathologic features and management decisions. Gastroenterol Hepatol (N Y). 2013; 9(10):640–651.

3. Jung, JT. Gastric polyps and protruding type gastric cancer. Clin Endosc. 2013; 46(3):243–247.

4. Carmack, SW, et al. The current spectrum of gastric polyps: a 1-year national study of over 120,000 patients. Am J Gastroenterol. 2009; 104(6):1524–1532.

5. Genta, RM, et al. No association between gastric fundic gland polyps and gastrointestinal neoplasia in a study of over 100,000 patients. Clin Gastroenterol Hepatol. 2009; 7(8):849–854.

6. Ba-Ssalamah, A, et al. Dedicated multidetector CT of the stomach: spectrum of diseases. Radiographics. 2003; 23(3):625–644.

 

Insko, EK, et al. Benign and malignant lesions of the stomach: evaluation of CT criteria for differentiation. Radiology. 2003; 228(1):166–171.

Cherukuri, R, et al. Giant hyperplastic polyps in the stomach: radiographic findings in seven patients. AJR Am J Roentgenol. 2000; 175(5):1445–1448.

Cho, GJ, et al. Peutz-Jeghers syndrome and the hamartomatous polyposis syndromes: radiologic-pathologic correlation. Radiographics. 1997; 17(3):785–791.

Harned, RK, et al. Extracolonic manifestations of the familial adenomatous polyposis syndromes. AJR Am J Roentgenol. 1991; 156(3):481–485.

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