Haggitt Level (Malignant Polyp Invasion)
Haggitt classification (Haggitt 1985) of invasion in a malignant colorectal polyp.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Haggitt level
- 4 — bowel-wall submucosa below the stalk (all sessile = level 4)
Result: Haggitt level 4: invasion below the stalk into the bowel-wall submucosa; higher metastasis risk. All sessile invasive polyps are level 4.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Level 0
- Carcinoma limited to the mucosa (carcinoma in situ / intramucosal); not truly invasive, no metastatic potential.
- Levels 1-3
- Invasion of the polyp head / neck / stalk. Low risk of adverse outcome; favorable pedunculated lesions often managed by polypectomy alone.
- Level 4
- Invasion into the bowel-wall submucosa below the stalk; all sessile invasive polyps by definition. Higher lymph-node-metastasis risk; surgical resection generally considered.
What you enter
- Haggitt level
How this is calculated
Haggitt RC, Glotzbach RE, Soffer EE, Wruble LD. Prognostic factors in colorectal carcinomas arising in adenomas: implications for lesions removed by endoscopic polypectomy. Gastroenterology. 1985;89(2):328-336. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.