What is the workup for a concern for gastric ulcer in a patient?

Workup for Concern for Gastric Ulcer

Upper endoscopy (esophagogastroduodenoscopy, EGD) with biopsy is the definitive diagnostic test for suspected gastric ulcer and should be performed to establish the diagnosis, exclude malignancy, and test for Helicobacter pylori infection. 1

Initial Diagnostic Approach

Endoscopy with Systematic Biopsy Protocol

For all suspected gastric ulcers, perform EGD with the following biopsy strategy:

• Biopsy all gastric ulcers from both the base and edges of the ulcer to exclude malignancy, as gastric ulcers can harbor adenocarcinoma 1
• The decision to biopsy may be individualized only in very low-risk scenarios (young non-Hispanic white patient taking NSAIDs with shallow, flat ulcer and associated erosions), but this is the exception rather than the rule 1
• Obtain additional biopsies from the remainder of the stomach (at least 2 from antrum within 2-3 cm of pylorus from lesser and greater curvature, and 2 from body) to test for H. pylori infection 1
• Place gastric body and antrum biopsies in separately labeled jars, as this is especially important in patients using proton pump inhibitors due to proximal migration of H. pylori 1

Helicobacter pylori Testing

All patients with suspected or confirmed gastric ulcer must undergo H. pylori testing, as this identifies the underlying cause and guides curative treatment: 2

• Non-invasive testing options include urea breath test (sensitivity 88-95%, specificity 95-100%) or stool antigen test (sensitivity 94%, specificity 92%) 2
• Critical pitfall to avoid: Stop proton pump inhibitors, antibiotics, and bismuth products for at least 2 weeks before testing to prevent false-negative results 2
• Do not rely on serology alone for treatment decisions, as it cannot confirm active infection 2

Laboratory Studies

Obtain routine laboratory studies in patients presenting with acute symptoms suggestive of complicated gastric ulcer: 2

• Complete blood count (to assess for anemia from bleeding)
• Metabolic panel
• Arterial blood gas analysis (if perforation suspected)
• Note that leukocytosis, metabolic acidosis, and elevated serum amylase are commonly associated with gastric perforation but are non-specific findings 2, 3

Imaging Studies (When Complications Suspected)

For Suspected Perforation

CT scan of the abdomen and pelvis with IV contrast is the first-line imaging modality (Strong recommendation, 1C): 3

• CT findings suggestive of perforation include pneumoperitoneum, unexplained intraperitoneal fluid, bowel wall thickening, mesenteric fat streaking, and extraluminal water-soluble contrast 3
• Perform chest/abdominal X-ray only when CT is not immediately available (Strong recommendation, 1C), recognizing that free air on X-ray is present in only 30-85% of perforations 3
• Up to 12% of patients with perforations may have a normal CT scan, requiring additional diagnostic measures 3

For Suspected Gastric Cancer

When gastric malignancy is suspected based on symptoms or endoscopic appearance:

• CT abdomen and pelvis with IV contrast and neutral oral contrast (water or dilute barium) should be performed 1
• CT findings concerning for malignancy include nodular or irregular wall thickening, soft tissue attenuation of wall thickening, perforation with ulcerated mass, lymphadenopathy, and distant metastases 1

Alternative Imaging (Limited Role)

• Upper GI series with double-contrast technique can diagnose gastritis and peptic ulcer disease when endoscopy is not available, showing ulcers with smooth radiating folds (benign) versus nodularity and irregular folds (concerning for malignancy) 1
• MRI has no routine role in diagnosing gastric ulcer, as CT is preferred for detecting complications like perforation 1

Critical Distinction: Benign-Appearing vs. Suspicious Ulcers

The endoscopic appearance combined with initial histology determines the need for surveillance:

• Benign-appearing ulcers (smooth margins, clean base, no nodularity) with benign histology at initial endoscopy have 100% sensitivity for ruling out malignancy and do not require routine surveillance endoscopy 4
• Suspicious features requiring biopsy and close follow-up include: dirty/necrotic base (sensitivity 79%), elevated border (sensitivity 94%), irregular border (sensitivity 91%), and larger ulcer diameter 4
• Malignant ulcers are significantly larger in diameter compared to benign ulcers 4

Follow-Up Strategy

For uncomplicated gastric ulcers with benign appearance and benign histology:

• Routine endoscopic surveillance is not recommended if both endoscopic appearance and initial biopsies are benign 4, 5
• This approach could reduce follow-up endoscopies by 77% without missing malignancy 4

For ulcers with any concerning features or incomplete initial biopsy:

• Repeat endoscopy at 6-8 weeks to document healing and obtain additional biopsies if not done initially 6
• A biopsy is always recommended to exclude malignancy, particularly in bleeding ulcers 1

Common Pitfalls to Avoid

1. Performing excessive surveillance endoscopy on clearly benign ulcers with benign histology—this practice is overused (64% surveillance rate in some centers) without detecting additional malignancy 5

2. Inadequate initial biopsy—only 22% of gastric ulcers are biopsied at initial endoscopy in some practices, leading to unnecessary surveillance 5

3. Testing for H. pylori while patient is on PPIs—this is the most common cause of false-negative results 2

4. Relying on imaging alone—laboratory tests and imaging cannot diagnose gastric ulcer definitively; they only detect complications 2

5. Missing H. pylori eradication confirmation—after treatment, confirm eradication with repeat testing to prevent ulcer recurrence 1, 7