What is the appropriate management for a patient’s rectal polyp?

Management of Rectal Polyps

For most rectal polyps, endoscopic resection is the preferred first-line treatment, with the specific approach determined by polyp size, morphology, and suspicion for malignancy. 1, 2

Initial Assessment and Risk Stratification

The management pathway depends critically on polyp characteristics identified during colonoscopy:

• Polyp size is the primary determinant of malignancy risk and resection strategy, with polyps ≥1 cm requiring complete removal due to increased cancer potential 3
• Morphology assessment using high-definition endoscopy should identify features of deep submucosal invasion (irregular surface pattern, ulceration, firmness, non-lifting sign after submucosal injection) that would preclude endoscopic resection 1
• Location in the rectum makes these lesions particularly amenable to endoscopic therapy compared to surgical options, given the significant morbidity (20-30%) and potential mortality (0.6-3.2%) associated with rectal surgery 1

Endoscopic Management Strategy

Benign Rectal Polyps

Piecemeal endoscopic mucosal resection (pEMR) is the preferred technique for most benign large rectal polyps, offering superior cost-effectiveness and lower morbidity compared to surgical alternatives 1:

• Complete endoscopic polypectomy is definitive treatment for dysplastic polyps, with surveillance colonoscopy (not colectomy) recommended after complete resection 4
• For large lesions requiring piecemeal resection, repeat colonoscopy at 3-6 months is necessary to detect and treat any residual tissue 4, 2
• Hyperplastic polyps ≥1 cm, sessile, or proximally located should be completely removed as they can progress to cancer through the serrated pathway 2

Malignant Polyps (T1 Lesions)

The decision tree for malignant polyps depends on depth of invasion and histologic features:

For favorable histology (well/moderately differentiated, clear margins ≥2 mm, no lymphovascular invasion, Haggitt 1-3 or sm1 invasion):

• Endoscopic resection alone is curative; surgery is unnecessary 1, 5
• Close surveillance is appropriate 1

For unfavorable histology (poor differentiation, positive margins, lymphovascular invasion, Haggitt 4 or sm2-3 invasion):

• Surgical resection with total mesorectal excision (TME) is indicated in healthy patients 1
• The risk of residual cancer or lymph node metastases exceeds 10%, justifying surgical intervention 1

Critical caveat: En bloc resection with adequate margins is essential for proper histologic assessment of malignant polyps 1, 2. Piecemeal resection of suspected malignant lesions compromises pathologic evaluation and should be avoided.

Surgical Alternatives for Complex Cases

When endoscopic resection is not feasible or appropriate:

• Transanal endoscopic microsurgery (TEMS) provides an intermediate option with 98.7% en bloc resection rates and 88.5% curative resection rates, superior to endoscopic submucosal dissection (ESD) 1
• However, pEMR remains preferable to TEMS for benign rectal polyps due to equivalent late recurrence rates (9.6% vs 13.8%), lower morbidity (13% vs 24%), shorter hospitalization, and significantly lower cost (~$2000 vs ~$7800) 1
• TEMS may be indicated for polyps occupying significant rectal circumference that are technically difficult for snare retrieval 1
• Laparoscopic surgery should be used in preference to open surgery when surgical resection is required, offering reduced 30-day mortality 1

Multidisciplinary Decision-Making

Establish communication among gastroenterologist, pathologist, surgeon, and patient for optimal management of malignant polyps 1:

• The decision to pursue adjuvant surgery after endoscopic resection of malignant polyps must weigh the risk of residual/metastatic disease against surgical mortality (1-8% depending on age) 1
• In an 85-year-old with comorbidities, foregoing surgery may be appropriate even with unfavorable features 1
• In a healthy 55-year-old with deep submucosal invasion or unfavorable histology, surgery is appropriate 1
• Patient values and preferences are paramount when risks are equipoise 1

Common Pitfalls to Avoid

• Do not perform routine pre-operative biopsy of suspected malignant polyps, as it rarely changes management and can cause sampling error 1
• Do not attempt piecemeal resection when malignancy is suspected and en bloc resection is feasible, as this compromises histologic assessment 1, 2
• Do not recommend surgery for completely resected pedunculated malignant polyps with favorable histology, as this exposes patients to unnecessary surgical risk 1, 5
• Do not delay repeat endoscopy beyond 3-6 months for large lesions removed piecemeal, as early detection of recurrence is critical 4, 2