A 65-year-old woman from Delhi undergoes colonoscopy for screening and is found to have a 2 cm polyp in the ascending colon. Histopathology shows a tubular adenoma with high-grade dysplasia but no invasion into the submucosa. The polyp was completely resected endoscopically with clear margins. What is the most appropriate next step in management?

## Pathological Diagnosis This polyp is a **high-grade dysplasia (HGD) adenoma** — the dysplasia is confined to the epithelium and does not breach the muscularis mucosae. Critically, **there is no invasion into the submucosa**, which means this is **NOT adenocarcinoma** — it is a precancerous lesion. **Key Point:** High-grade dysplasia (HGD) = severe dysplasia confined to the epithelium. Once the muscularis mucosae is breached, it becomes invasive carcinoma and requires surgical resection. ## Polyp Classification & Management | Finding | Pathology | Management | |---------|-----------|-------------| | **Low-grade dysplasia (LGD)** | Dysplasia in epithelium only | Surveillance in 5–10 years | | **High-grade dysplasia (HGD)** | Severe dysplasia, no invasion | Surveillance in 1 year (if completely resected) | | **Invasive carcinoma (T1)** | Invasion into submucosa/muscularis propria | Surgical resection | | **Invasive carcinoma (T2+)** | Invasion beyond muscularis propria | Surgical resection | ## Rationale for Correct Answer **Surveillance colonoscopy in 1 year** is the most appropriate next step because: 1. **Complete endoscopic resection:** The polyp was completely removed with clear margins — no residual dysplasia remains in the colon. 2. **No invasion:** HGD without submucosal invasion is a precancerous lesion, not cancer — it does not require surgery. 3. **Risk of metachronous lesions:** Patients with adenomas are at increased risk of developing new adenomas elsewhere in the colon; surveillance detects these early. 4. **Guideline-based:** USPSTF and ASGE guidelines recommend surveillance colonoscopy at 1 year for completely resected HGD adenomas to ensure no residual disease and to detect new lesions. **High-Yield:** The key distinction is: - **HGD (no invasion) → Endoscopic resection + surveillance** - **Invasive carcinoma (T1 or deeper) → Surgical resection** ## Why Other Options Are Wrong **3-month repeat colonoscopy** is too aggressive — 1 year is the standard interval for HGD adenomas. Earlier repeat is reserved for incomplete resection or sessile serrated polyps. **Surgical resection** is unnecessary because there is no invasion into the submucosa. Surgery is indicated only for invasive carcinoma (T1 or deeper). Performing surgery for HGD alone would be overtreatment. **Annual faecal occult blood testing** is inadequate surveillance for a patient with a history of adenoma. Colonoscopy is the gold standard for surveillance and allows detection and removal of new lesions. **Clinical Pearl:** The distinction between HGD and T1 carcinoma is critical: - **HGD:** Dysplasia confined to epithelium → endoscopic management + surveillance - **T1 carcinoma:** Invasion into submucosa → requires surgical resection (10–15% risk of lymph node metastasis) If this polyp had shown invasion into the submucosa, surgical resection would be mandatory. [cite:Robbins & Cotran 10e Ch 17]