Clinical Definition
Intestinal polyps are discrete mass lesions that protrude into the intestinal lumen from the mucosal surface. Histologically, they are classified into two primary categories: Neoplastic polyps (e.g., Adenomas, Sessile Serrated Lesions) which possess malignant potential via the adenoma-carcinoma sequence, and Non-neoplastic polyps (e.g., Hyperplastic, Inflammatory, Hamartomatous) which generally lack malignant potential. Accurate histological classification is critical for determining surveillance intervals.
Clinical Coding & Classification
| System / Category | Code(s) | Description |
|---|---|---|
| ICD-10-CM | K63.5 | Polyp of colon (Hyperplastic/Inflammatory) |
| ICD-10-CM | D12.6 | Benign neoplasm of colon, unspecified (Adenoma) |
| CPT (Surgical) | 45385 | Colonoscopy with removal of tumor(s), polyp(s) by snare technique |
| CPT (Surgical) | 45384 | Colonoscopy with removal of tumor(s), polyp(s) by hot biopsy forceps |
| Pathology | 88305 | Level IV – Surgical pathology, gross and microscopic examination (Polyp) |
Epidemiology & Statistics
Colonic polyps are highly prevalent, occurring in approximately 30% to 50% of adults over the age of 50 in Western populations. Incidence correlates strongly with age, male gender, and high body mass index (BMI). Adenomatous polyps are detected in roughly 25% of screening colonoscopies in average-risk individuals aged 50 and older.
Pathophysiology (Mechanism)
The progression from benign polyp to colorectal cancer is described by the Adenoma-Carcinoma Sequence. Key molecular pathways include:
1. Chromosomal Instability (CIN) Pathway: Involves mutations in the APC tumor suppressor gene (seen in 80% of sporadic adenomas), followed by KRAS activation and TP53 inactivation.
2. Serrated Neoplasia Pathway: Characterized by CpG island methylator phenotype (CIMP) and BRAF mutations, leading to sessile serrated lesions which are precursors to sporadic microsatellite instability (MSI) cancers.
Standard Management Protocols
The gold standard for management is endoscopic resection (Polypectomy) followed by histopathological risk stratification.
- Procedural Interventions:
- Snare Polypectomy: Standard technique for pedunculated polyps.
- Endoscopic Mucosal Resection (EMR): Indicated for large sessile or flat lesions (>20mm) to ensure complete removal of the neoplastic tissue.
- Surveillance Guidelines:
- Follow-up intervals are determined by the number, size, and histology of resected polyps (e.g., US Multi-Society Task Force guidelines). High-risk features (e.g., >3 adenomas, villous histology, high-grade dysplasia) warrant shorter intervals (e.g., 3 years).
- Pharmacological Classes (Chemoprevention):
- NSAIDs / COX-2 Inhibitors: (e.g., Aspirin, Celecoxib) May be considered in high-risk populations (e.g., Familial Adenomatous Polyposis) to suppress polyp regression, though risks of GI toxicity must be weighed.
Healthcare Resource Utilization
Management of intestinal polyps represents a significant portion of gastroenterology expenditure:
- Screening Volume: Colonoscopy is one of the most frequently performed medical procedures in the US, driven by colorectal cancer screening mandates.
- Pathology Burden: Histological analysis of all resected polyps contributes substantially to laboratory resource utilization.
