What is the treatment for dysplasia of a colonic polyp?

Treatment of Dysplastic Colonic Polyps

For sporadic colonic polyps with dysplasia, complete endoscopic polypectomy is the definitive treatment, with surveillance colonoscopy rather than colectomy recommended for completely resected lesions. 1

Classification Framework

The treatment approach depends critically on whether the dysplastic polyp occurs in the context of inflammatory bowel disease (IBD) or represents a sporadic adenoma:

Sporadic Adenomas (Non-IBD Context)

Endoscopic polypectomy is the standard treatment for all dysplastic polyps that can be completely removed. 2

• Complete endoscopic resection is curative for polyps with dysplasia when clear margins are achieved 1
• All polyps ≥1 cm should be removed upon detection, as these carry the highest malignancy risk 2
• After complete resection, surveillance colonoscopy is preferred over surgical resection 1

IBD-Associated Dysplasia

The treatment algorithm for IBD patients is more complex and depends on lesion morphology:

Polypoid (Adenoma-Like) Dysplastic Lesions

Complete polypectomy is adequate treatment provided:

• The lesion can be completely excised 1
• Margins are free of dysplasia 1
• No flat dysplasia exists elsewhere in the colon 1
• Biopsies from surrounding flat mucosa show no dysplasia 1

Non-Polypoid Dysplastic Lesions

After complete endoscopic removal, surveillance is suggested rather than colectomy 1

However, this is a conditional recommendation given:

• Higher technical difficulty ensuring complete removal 1
• Potentially higher CRC risk compared to polypoid lesions 1
• Larger lesions requiring piecemeal resection should have repeat colonoscopy at 3-6 months 1

Non-Adenoma-Like Raised Lesions (Former "DALM")

Colectomy is recommended regardless of dysplasia grade due to high association with synchronous or metachronous carcinoma 1

• These include velvety patches, plaques, irregular bumps, wart-like thickenings, and broad-based masses 1
• Endoscopic mucosal resection has been attempted but shows higher recurrence (14% vs 0% for sporadic lesions) 1

Flat (Endoscopically Invisible) Dysplasia

High-grade dysplasia: Colectomy is warranted because 42-67% already have concurrent CRC 1

Low-grade dysplasia: Individualized decision between colectomy versus yearly surveillance after thorough discussion 1

Surveillance After Endoscopic Resection

Sporadic Adenomas

Follow-up colonoscopy timing depends on polyp characteristics:

• Initial surveillance within 1 year to detect recurrence or missed lesions 2
• Subsequently every 2 years for multiple polyps, every 3 years for single adenoma 2
• Polyps >1 cm with high-grade dysplasia warrant close follow-up as they carry higher risk 3

IBD-Associated Polypoid Dysplasia

More intensive surveillance than standard IBD surveillance is reasonable 1

• Larger sessile lesions removed piecemeal should have repeat examination at 3-6 months 1
• If negative, extend to yearly intervals 1
• Annualized CRC incidence after polypoid dysplasia resection is 0.5% 1

Critical Pitfalls to Avoid

Always confirm dysplasia with expert GI pathologist review before making treatment decisions 1

Distinguish IBD-associated from sporadic polyps:

• Polyps proximal to areas of current or historical colitis involvement are considered sporadic and treated accordingly 1
• This distinction fundamentally changes management from potential colectomy to simple polypectomy 1

Ensure complete lesion characterization:

• Examine entire colon for synchronous flat dysplasia before deciding on polypectomy alone 1
• Biopsy flat mucosa surrounding dysplastic polyps in IBD patients 1

Recognize high-risk features requiring surgical consideration:

• Sessile or pseudo-pedunculated polyps with invasive cancer 2
• Poorly differentiated cancer, lymphovascular invasion, or positive margins 2
• Non-adenoma-like morphology in IBD patients 1

Risk Stratification

High-grade dysplasia in polyps >1 cm carries significant risk for subsequent advanced neoplasia 3

Multiple adenomas (≥3) at baseline strongly predict recurrence:

• 4.3-fold increased risk of overall recurrence 4
• 2.5-fold increased risk of advanced adenoma recurrence 4
• Male gender also independently predicts advanced adenoma recurrence 4

Diminutive polyps (≤5 mm) with high-grade dysplasia do not significantly increase advanced adenoma risk compared to low-grade dysplasia 5