Can gastrointestinal (GI) tuberculosis present as gastritis without granulomatous tissue?

Gastric Tuberculosis Can Present as Gastritis Without Granulomatous Tissue

Yes, tuberculosis in the GI tract can present as gastritis without granulomatous tissue, though this is an atypical presentation that requires a high index of suspicion for diagnosis. While granulomatous inflammation with caseating necrosis is the hallmark histological finding in tuberculosis, the absence of granulomas does not exclude the diagnosis, particularly in early or partially treated disease.

Diagnostic Considerations

Clinical Presentation

• Patients with gastric tuberculosis typically present with:
  • Epigastric pain (most common)
  • Weight loss
  • Vomiting
  • Fever
  • Upper GI bleeding
  • Gastric outlet obstruction 1, 2

Endoscopic Findings

• Gastric TB may appear endoscopically as:
  • Ulcerative lesions
  • Mass-like lesions
  • Diffuse gastritis
  • Pseudopolypoid gastritis
  • Infiltrated mucosa 1, 3

Histopathological Features

• Classic findings include:
  • Caseating granulomas
  • Acid-fast bacilli on special stains
• However, in early disease or partially treated cases:
  • Non-specific inflammation may be the only finding
  • Granulomas may be absent or non-caseating
  • Acid-fast bacilli may be scarce or absent 4

Diagnostic Approach for Suspected Gastric TB Without Granulomas

1. Comprehensive Endoscopic Evaluation

   • Multiple and deep biopsies are essential
   • Consider endoscopic ultrasound-guided biopsies for submucosal lesions 1

2. Advanced Microbiological Testing

   • PCR for Mycobacterium tuberculosis DNA on biopsy specimens
   • Xpert MTB/RIF assay
   • Mycobacterial cultures (may take 6-8 weeks) 1

3. Imaging Studies

   • Abdominal CT scan to evaluate for:
     • Wall thickening
     • Mass lesions
     • Regional lymphadenopathy
     • Concurrent involvement of other abdominal organs 5

4. Additional Testing

   • Tuberculin skin test or interferon-gamma release assay
   • Chest X-ray to identify concurrent pulmonary TB (present in only 15-20% of GI TB cases) 4
   • Evaluation for TB in other sites

Management Approach

When gastric TB is suspected despite absence of granulomas:

1. Diagnostic Trial of Anti-TB Therapy

   • In endemic areas or high-risk patients with compatible clinical picture
   • Clinical and endoscopic response within 2-3 months supports the diagnosis 5

2. Standard Treatment Regimen

   • 6-month regimen:
     • Initial phase (2 months): Isoniazid, Rifampin, Pyrazinamide, and Ethambutol
     • Continuation phase (4 months): Isoniazid and Rifampin 5, 6

3. Follow-up

   • Endoscopic reassessment after 2-3 months of therapy
   • Complete resolution of lesions typically occurs with appropriate therapy 7

Important Caveats

• Gastric TB is rare compared to ileocecal TB, which is the most common site of GI involvement 5
• Differential diagnosis includes:
  • Crohn's disease
  • Peptic ulcer disease
  • Gastric malignancy
  • Other granulomatous conditions (sarcoidosis, fungal infections)
• Diagnosis is often delayed due to nonspecific presentation and low index of suspicion
• In immunocompromised patients, atypical presentations without granulomas are more common 5

The American Thoracic Society and Infectious Diseases Society of America recommend that abdominal tuberculosis, including gastric TB, be treated with the standard 6-month regimen used for pulmonary TB 6, 5. Surgical intervention is reserved for complications or diagnostic uncertainty.