A 58-year-old man undergoes screening colonoscopy and is found to have a 1.2 cm pedunculated adenomatous polyp in the sigmoid colon. The polyp has a well-defined stalk (pedicle) and a lobulated head. The endoscopist plans to remove the polyp using a hot snare technique. The site marked **D** in the diagram indicates where the snare should be positioned. Which of the following best describes why the location marked **D** is the optimal site for snare polypectomy in this pedunculated polyp?

Explanation

## Why "Positioning the snare at the stalk base allows complete resection of the polyp head while minimizing risk of incomplete resection and recurrence" is right Pedunculated polyps have a distinct advantage over sessile lesions: the stalk provides a natural plane of separation. Positioning the snare at the stalk (site **D**) — specifically at the junction between the stalk and the normal mucosa — ensures complete removal of the entire polyp head while leaving the stalk base to be cauterized. This technique is endorsed by ASGE guidelines and Harrison's textbook because pedunculated morphology carries lower invasion risk and the stalk-based approach minimizes residual adenomatous tissue. Hot snare electrocautery at this site achieves hemostasis and complete ablation of the stalk base, reducing recurrence risk. ## Why each distractor is wrong - **"Positioning the snare at the polyp head allows direct cauterization of the lobulated mucosa, reducing malignant transformation risk"**: Snaring at the polyp head rather than the stalk would leave the stalk behind, resulting in incomplete resection and potential recurrence. Malignant transformation is a histologic property determined at diagnosis, not prevented by where the snare is placed. The goal is complete removal, not transformation prevention. - **"Positioning the snare at the junction between stalk and submucosa prevents perforation by avoiding the muscularis propria"**: While perforation risk is a valid concern, the stalk is composed of submucosa and does not contain the muscularis propria — the muscularis is beneath the submucosa. Proper snare placement at the stalk base does not "avoid" the muscularis; rather, it removes the polyp completely while the cautery seals the stalk base. This distractor conflates anatomic layers. - **"Positioning the snare proximal to the stalk allows retrieval of the polyp specimen without fragmentation during withdrawal"**: Specimen retrieval technique (using a net or trap) is separate from snare placement. Proximal snaring would leave distal stalk tissue behind, causing incomplete resection. Fragmentation during withdrawal is managed by retrieval devices, not by snare positioning. **High-Yield:** Pedunculated polyps are resected by snaring at the stalk base with hot snare electrocautery — the stalk provides a natural plane of cleavage and lower invasion risk compared to sessile lesions. [cite: Harrison 21e Ch 79; ASGE Guidelines on Polypectomy Technique]