Haggitt classification

Haggitt classification

A histologic system for quantifying the extent of epithelial invasion into pedunculated malignant colorectal polyps.

Haggitt classification
Level 0—Carcinoma in situ or intramucosal carcinoma; non-invasive.
Level 1—Carcinoma invades muscularis mucosa to submucosa; limited to head of polyp.
Level 2—Carcinoma invades neck of polyps.
Level 3—Carcinoma invades any part of the stalk.
Level 4—Carcinoma invades submucosa of bowel wall, below polyp stalk but above muscularis propria.