3. Colorectal Polyps

 
 

1. Overview

  • Definition: Colorectal polyps are mucosal growths in the colon or rectum, ranging from benign hyperplastic polyps to neoplastic adenomas.
  • Significance: Some polyps, particularly adenomatous and serrated polyps, carry a risk of malignant transformation into colorectal cancer (CRC).

2. Types of Colorectal Polyps

  1. Hyperplastic Polyps:
    • Common, benign, and low malignancy risk.
    • Frequently found in the rectosigmoid colon.
  2. Adenomatous Polyps:
    • Neoplastic; risk factors for CRC:
      • Larger size (>10 mm).
      • Villous histology or high-grade dysplasia.
    • Subtypes:
      • Tubular adenomas (most common).
      • Tubulovillous adenomas.
      • Villous adenomas (highest malignant potential).
  3. Serrated Polyps:
    • Types: Sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs).
    • Associated with BRAF mutations and proximal CRC.
  4. Inflammatory Polyps:
    • Associated with inflammatory bowel diseases (IBD) like Crohn’s or ulcerative colitis.

3. Screening and Surveillance

Population-Level Screening:

  • BSG and ESGE Recommendations:
    • Biennial fecal immunochemical testing (FIT) for individuals aged 50–74.
    • Colonoscopy for FIT-positive patients.

Surveillance After Polypectomy:

  • Low-risk polyps:
    • 1–2 small adenomas (<10 mm): Repeat colonoscopy in 5–10 years.
  • High-risk polyps:
    • ≥3 adenomas, ≥10 mm, or high-grade dysplasia: Repeat in 3 years.

Serrated Polyposis Syndrome (WHO, 2019):

  • ≥5 serrated polyps ≥5 mm proximal to the rectum (2 ≥10 mm), or >20 serrated polyps.
  • Surveillance: Annual colonoscopy for high-risk cases.

Family History Surveillance:

  • First-degree relative (FDR) with CRC <50 years:
    • Start colonoscopy at age 40, repeat every 5 years.
  • Multiple FDRs with CRC: Begin screening 10 years earlier than youngest family diagnosis.

4. Risk Stratification (BSG Guidelines, 2020)

  • Stratify based on:
    • Number of polyps.
    • Size (≥10 mm).
    • Histological features (villous or dysplastic).
  • High-risk patients undergo more frequent surveillance (1–3 years).

5. 2-Week Referral Criteria for Suspected Colorectal Cancer

  • Symptoms necessitating urgent referral:
    • Aged >40 years with unexplained weight loss and abdominal pain.
    • Aged >50 years with rectal bleeding.
    • Aged >60 years with iron-deficiency anemia or change in bowel habits.
    • Any age with occult blood detected in fecal testing.
    • Consider urgent referral for unexplained rectal or abdominal mass, or individuals aged <50 years with rectal bleeding plus anemia, abdominal pain, weight loss, or change in bowel habits.

6. Management of Colorectal Polyps

  1. Polypectomy Techniques:
    • Cold snare polypectomy (CSP): Preferred for polyps <10 mm.
    • Hot snare polypectomy (HSP): For larger or dysplastic polyps.
  2. Endoscopic Mucosal Resection (EMR):
    • Used for sessile or flat polyps >20 mm.
    • Classification Systems:
      • Pit Pattern (Kudo Classification): Differentiates benign from malignant polyps using magnification endoscopy.
        • Type I-II: Non-neoplastic.
        • Type III-V: Neoplastic.
      • NICE Classification: Guides optical diagnosis of colorectal polyps.
        • Type 1: Hyperplastic.
        • Type 2: Adenomatous.
        • Type 3: Deep submucosal invasive cancer.
      • Morphology-Based Classification:
        • IP: Pedunculated polyps.
        • IS: Sessile polyps.
        • ISP: Sessile serrated polyps.
        • LST (Lateral Spreading Tumor): Classified as granular or non-granular.
  3. Haggitt Classification for Pedunculated Polyps:
    • Level 0: In situ carcinoma.
    • Level 1: Invasion into the submucosa, limited to the head of the polyp.
    • Level 2: Invasion into the neck of the polyp.
    • Level 3: Invasion into the stalk of the polyp.
    • Level 4: Invasion beyond the stalk into the submucosa of the bowel wall.
    • Lymphatic Spread Risk:
      • Level 1-2: Low risk (<1%).
      • Level 3-4: High risk (>10%).
  4. Surgical Resection:
    • Indicated for non-resectable polyps or those with invasive carcinoma.

7. Additional Recommendations (ESGE)

  • Frequent monitoring for patients with advanced lesions or high polyp burden.
  • Education for patients regarding the importance of follow-up.

References

  1. BSG Guidelines for Surveillance of Colorectal Polyps
  2. ESGE Guidelines for Colorectal Cancer Screening
  3. Principles for Evaluation After Polypectomy (WEO)
  4. Evidence-Based Guidelines for Management of Colorectal Polyps