What is the recommended lab workup for a patient presenting with epigastric pain, firmness, and unintentional weight loss?

Laboratory Workup for Epigastric Pain, Firmness, and Unintentional Weight Loss

For patients presenting with epigastric pain, firmness, and unintentional weight loss, a comprehensive laboratory workup with endoscopy and CT imaging with IV contrast is essential to rule out malignancy, which should be the primary concern.

Initial Laboratory Evaluation

Basic Laboratory Tests

• Complete blood count (CBC) - to assess for anemia, infection, or inflammatory processes
• Comprehensive metabolic panel (CMP) - to evaluate liver, kidney function, and electrolytes
• Amylase and lipase - to rule out pancreatic pathology
• Helicobacter pylori testing - stool antigen or urea breath test

Additional Blood Tests

• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) - to assess for inflammatory conditions
• Thyroid function tests - as thyroid disorders can cause weight loss
• Fasting blood glucose - to screen for diabetes, which can cause gastroparesis 1
• Carcinoembryonic antigen (CEA) and CA 19-9 - tumor markers that may be elevated in gastrointestinal malignancies

Imaging Studies

First-Line Imaging

• CT abdomen and pelvis with IV contrast - essential for evaluating:
  • Gastric wall thickening or masses
  • Nodular or irregular enhancement
  • Lymphadenopathy
  • Distant metastases 2

The CT should be performed with:

• IV contrast to assess wall thickening and enhancement patterns
• Neutral oral contrast (water or dilute barium) to delineate the intraluminal space 2

Specialized Imaging (if indicated)

• Upper GI series with double-contrast technique - can identify:
  • Ulcers with nodularity
  • Mass effect
  • Coarse, lobulated, or irregular radiating folds 2
  • Scirrhous gastric carcinoma (which may be missed on endoscopy) 2

Endoscopic Evaluation

Endoscopy with biopsy is the reference standard for diagnosing gastric cancer and should be performed in all patients with epigastric pain, firmness, and unintentional weight loss 2, 3.

• Upper endoscopy (esophagogastroduodenoscopy or EGD) - allows direct visualization and biopsy of suspicious lesions
• Colonoscopy - should be considered, especially in older patients, as the diagnostic yield is significant 3

Clinical Considerations

Red Flags Requiring Urgent Evaluation

• Unintentional weight loss is a significant concern and substantially increases the likelihood of finding clinically significant endoscopic findings 3
• The combination of postprandial pain and weight loss is highly suspicious for mesenteric artery stenosis or malignancy 2, 4
• Epigastric firmness may represent a mass or significant inflammation

Common Pitfalls to Avoid

1. Delaying endoscopy - The diagnostic yield of endoscopy for investigation of patients with unintentional weight loss is significant and should be part of baseline evaluation 3
2. Overlooking gastroparesis - Consider gastric emptying studies if symptoms include early satiety, nausea, and vomiting 1, 5
3. Missing mesenteric ischemia - In patients with postprandial pain and weight loss, mesenteric duplex ultrasound is appropriate (rated 8/9 for appropriateness) 2
4. Incomplete imaging - CT abdomen without pelvis may miss distant metastases 2

Algorithmic Approach

1. Initial laboratory tests: CBC, CMP, amylase/lipase, H. pylori testing
2. Imaging: CT abdomen/pelvis with IV contrast
3. Endoscopy: Upper endoscopy with biopsies of any suspicious areas
4. Based on initial findings:
   • If CT shows mesenteric vascular concerns: Add mesenteric duplex ultrasound
   • If gastroparesis is suspected: Add gastric emptying study
   • If colonoscopic findings are suspected: Add colonoscopy
   • If biliary pathology is suspected: Add liver function tests and abdominal ultrasound

The combination of epigastric pain, firmness, and unintentional weight loss should always raise concern for malignancy until proven otherwise, with gastric cancer being a primary consideration 2.