A 55-year-old woman undergoes colonoscopy which reveals a 25 mm flat lesion in the sigmoid colon classified as Paris type IIa + IIc. The lesion is removed by endoscopic mucosal resection (EMR) and histology shows T1 (sm2) colorectal adenocarcinoma with poor differentiation and lymphovascular invasion. What is the recommended management?
- A Surveillance colonoscopy at 3 months
- B Oncological resection (sigmoid colectomy with lymph node harvest) ✓
- C Repeat EMR to achieve clear margins
- D Adjuvant radiotherapy to the resection site
Correct answer: B. Oncological resection (sigmoid colectomy with lymph node harvest)
Explanation
T1 colorectal cancers are subclassified by depth of submucosal invasion (sm1 ≤1 mm, sm2 1–2 mm, sm3 >2 mm). Features conferring high risk of lymph node metastasis and indicating surgical resection include: deep submucosal invasion (sm2–3), poor differentiation (G3), lymphovascular invasion, tumour budding grade 2/3, and positive resection margins. This patient has sm2, poor differentiation, AND lymphovascular invasion — all high-risk features — mandating formal oncological resection with adequate lymph node harvest rather than endoscopic surveillance.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.