What is the most appropriate management for a 20-mm laterally spreading tumor (LST) in the cecum, confined to the mucosa?

Management of a 20-mm Laterally Spreading Tumor in the Cecum

Piecemeal endoscopic mucosal resection (EMR) is the most appropriate management for a 20-mm laterally spreading tumor (LST) in the cecum that appears confined to the mucosa. 1

Assessment and Rationale

Initial Lesion Evaluation

• The 20-mm LST in the cecum requires careful assessment before determining the optimal removal strategy:
  • Size: At 20 mm, this qualifies as a "large" non-pedunculated colorectal lesion
  • Location: Cecal location increases risk of adverse events
  • Morphology: LST confined to the mucosa suggests no deep submucosal invasion

Why EMR is Appropriate

The US Multi-Society Task Force on Colorectal Cancer specifically recommends:

• EMR as the preferred treatment method for large (≥20 mm) non-pedunculated colorectal lesions 1
• This approach provides complete resection while avoiding the higher morbidity, mortality, and cost associated with surgical treatment

Why Piecemeal EMR vs. Other Options

1. Versus ESD (Option B):

   • While ESD allows en bloc resection, it's primarily indicated when there's concern for submucosal invasion
   • For a lesion confined to the mucosa without high-risk features, piecemeal EMR offers similar outcomes with lower procedural risk 1
   • The Chinese Society of Clinical Oncology guidelines support piecemeal EMR for mucosal lesions >20 mm 1

2. Versus Surgery (Option C):

   • Surgical right hemicolectomy is unnecessarily invasive for a mucosal lesion
   • The US Multi-Society Task Force guidelines emphasize that endoscopic resection can obviate the need for surgery 1

3. Versus Ablation (Option D):

   • Guidelines specifically recommend against using ablative techniques like argon plasma coagulation as primary treatment for visible lesions 1

Technical Considerations for EMR

Procedural Approach

1. Pre-procedure planning:

   • Document lesion characteristics with photo documentation
   • Use enhanced imaging techniques to confirm mucosal confinement

2. Injection technique:

   • Use a submucosal injection solution with contrast agent (indigo carmine or methylene blue) 1
   • Consider a viscous injection solution (hydroxyethyl starch, Eleview, ORISE Gel) to facilitate resection in fewer pieces 1

3. Resection technique:

   • Perform snare resection of all visible tissue in the safest minimum number of pieces 1
   • Avoid ablative techniques on visible residual tissue 1
   • Consider adjuvant thermal ablation (snare tip soft coagulation) of post-EMR margins where no visible adenoma remains 2

4. Post-resection management:

   • Carefully inspect the resection site for immediate complications
   • Consider prophylactic closure of the resection defect with clips (especially for right colon lesions ≥20 mm) 1

Surveillance Protocol

• First surveillance colonoscopy at 6 months
• Second surveillance at 1 year
• Third surveillance at 3 years 1
• Use enhanced imaging techniques to examine the post-mucosectomy scar site

Potential Complications and Management

• Bleeding: Treat intraprocedural bleeding with endoscopic coagulation or clips
• Perforation: Perform immediate clip closure if identified
• Recurrence: Occurs in approximately 6% of cases with STSC of margins 2, can usually be managed endoscopically

Special Considerations

• If the LST had high-risk features (non-granular type with depression, dominant nodule), ESD would be preferred for en bloc resection 1
• Cecal location increases the risk of adverse events, requiring careful technique 1
• Complete documentation of the resection site is essential for future surveillance

By following this approach, complete removal of the LST can be achieved while minimizing risks and maintaining excellent clinical outcomes.