What is the recommended surgical procedure for a patient with a 45cm tubular adenoma in the ascending colon?

Surgical Management of Large Tubular Adenoma in the Ascending Colon

For a 45mm tubular adenoma in the ascending colon, the recommended surgical procedure is a right hemicolectomy with en bloc removal of regional lymph nodes. 1

Understanding the Clinical Context

The size of this lesion (45mm) places it well beyond the threshold for routine endoscopic management and into the category requiring surgical consideration. While endoscopic mucosal resection (EMR) is the preferred treatment for large non-pedunculated lesions ≥20mm 1, lesions of this size (45mm) in the ascending colon present specific challenges:

• Size matters significantly: Each 1mm increment in adenoma diameter beyond 20mm increases the need for surgery by 8% and the risk of complications by 4% 2
• Location is critical: Cecal and ascending colon locations are independent risk factors for requiring surgical intervention (OR 5.97) 2
• At 45mm, this lesion is more than double the size threshold where endoscopic resection becomes increasingly risky and less likely to achieve complete resection

The Surgical Approach

Right hemicolectomy with en bloc removal of regional lymph nodes is the standard procedure for ascending colon lesions requiring surgical resection. 1 This involves:

• Excision of the primary tumor with safe margins 1
• Removal of vessels and associated mesocolon containing lymphatic channels and nodes 1
• Median laparotomy incision with examination of the liver, pelvis, and ovaries (in women) 1
• Careful examination of the entire bowel during surgery, as multiple synchronous lesions may be present 1

Why Surgery Over Endoscopy?

While EMR is recommended for large non-pedunculated lesions ≥20mm 1, several factors make surgical resection more appropriate for this 45mm lesion:

• Incomplete resection risk: Large lesions have high incomplete resection rates with endoscopic techniques 1
• Anatomic location: Right colon location independently predicts need for surgery 2
• Malignancy risk: At this size, there is approximately 10-15% risk of lymph node metastases if invasive cancer is present 1
• Technical feasibility: Lesions this large are difficult to remove endoscopically in the safest minimum number of pieces 1

Critical Pre-Operative Considerations

Before proceeding to surgery, ensure:

• Complete colonoscopy to rule out synchronous polyps 1
• Pathologic review if any prior biopsy was performed to assess for invasive cancer 1
• Staging workup including CBC, chemistry profile, CEA, and CT imaging of chest/abdomen/pelvis if malignancy is suspected 1
• Marking of the lesion site if not already done 1

Common Pitfalls to Avoid

• Do not attempt piecemeal endoscopic resection of a 45mm lesion in the ascending colon—prior failed attempts increase risk of incomplete resection and recurrence 1
• Do not use tattoo with carbon particle suspension in the submucosal injection if endoscopic assessment is attempted, as this causes fibrosis and complicates future intervention 1
• Do not delay surgical consultation for lesions of this size in this location—the combination of size and anatomic location strongly favors upfront surgical management 2

Post-Operative Management

Following right hemicolectomy:

• Surveillance colonoscopy at appropriate intervals 1
• No adjuvant chemotherapy if final pathology shows stage I disease (adenoma without invasive cancer or T1 lesion) 1
• Consider adjuvant therapy only if invasive cancer with unfavorable features is found on final pathology 1