A 30-year-old man with familial adenomatous polyposis (APC mutation) undergoes proctocolectomy with ileal pouch–anal anastomosis (IPAA). Six months later, endoscopy reveals multiple polyps in the retained rectal cuff. The correct term for this region and the most important follow-up action are:
- A Ileal pouch; annual pouchoscopy with polypectomy
- B Retained rectum; immediate completion proctectomy
- C Transition zone (ATZ); ATZ surveillance every 6 months with biopsy or mucosectomy ✓
- D Afferent limb; no action needed
Correct answer: C. Transition zone (ATZ); ATZ surveillance every 6 months with biopsy or mucosectomy
Explanation
In FAP patients undergoing IPAA, the anal transition zone (ATZ) — the columnar mucosa between the dentate line and the anastomosis — retains adenoma risk if mucosectomy was not performed. Current guidelines recommend surveillance of the ATZ every 6 months with biopsy or mucosectomy of polyps; the risk of dysplasia/cancer in the retained ATZ necessitates this close follow-up.
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.