Select the lesion morphology from the endoscopy report to visualize the Paris classification profile.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Description of the macroscopic appearance of superficial gastrointestinal lesions (Oesophagus, Stomach, Duodenum, Colon)
Standardizing communication between endoscopists regarding the "resectability" of a polyp or tumour
Predicting the risk of deep submucosal (SM) invasion based on shape
Selecting the appropriate resection technique (Cold Snare, EMR, or ESD)
Defining "Superficial"
A "superficial" lesion (Type 0) is one where the endoscopic appearance suggests that it is limited to the mucosa or submucosa, without invasion of the muscularis propria.
Section 2
Formula & Logic
Type 0: Superficial Lesions
01
Type 0-Ip: Pedunculated (has a stalk).
02
Type 0-Is: Sessile (broad-based, height > 2.5 mm).
03
Type 0-IIa: Slightly elevated (height < 2.5 mm).
04
Type 0-IIb: Flat (level with the surrounding mucosa).
05
Type 0-IIc: Slightly depressed (below the surrounding mucosa).
06
Type 0-III: Excavated (ulcerated depth).
Invasion Risk Profile
Protruding (Ip/Is)
Low SM invasion risk (unless large)
Flat-Depressed (IIc)
High SM invasion risk (> 30% even if small)
Excavated (III)
Highest risk; suspicious for deep malignancy
The 2.5mm Rule
The distinction between "Sessile" (Is) and "Elevated" (IIa) is a height of 2.5 mm (approximately the diameter of a closed biopsy forceps).
Section 3
Pearls/Pitfalls
The Danger of 0-IIc
Depressed lesions (IIc) are the "wolves in sheep's clothing." Because they grow downward rather than upward, they can reach the submucosa even when they are < 10 mm in diameter. Any depressed component in a larger flat lesion (IIa + IIc) should be targeted with magnified NBI (JNET/Kudo) for signs of invasive cancer.
Lateral Spreading Tumours (LST)
LSTs are superficial lesions > 10 mm that grow horizontally. They are further divided into LST-G (Granular) and LST-NG (Non-granular). LST-NG with a 0-IIc component has the highest rate of multi-focal submucosal invasion and typically requires ESD for safe removal.
Clinical Pearls
Paris 0-Ip (Pedunculated) polyps are usually adenomatous and safe for snare polypectomy
Non-lifting (following submucosal injection) is a strong contraindication for EMR in Paris 0-IIc/0-III lesions
Type 0-I and 0-II lesions in the oesophagus (especially in Barrett's) require meticulous mapping before ablation
Section 4
Next Steps
Management Action
01
Paris 0-Ip/Is/IIa: Standard EMR or Polypectomy.
02
Paris 0-IIc or LST-NG: Consider referral for EUS or ESD.
03
Paris 0-III: High risk of deep invasion; biopsy and stage.
Complementary Tools
JNET Classification (Vessels)
Kudo Pit Pattern (Pits)
NICE Classification (NBI)
Section 5
Evidence Appraisal
The International Consensus
The Paris endoscopic classification of superficial gastrointestinal lesions: esophagus, stomach, and colon: November 30 to December 1, 2002.
The Participants in the Paris Workshop. • Gastrointestinal Endoscopy. 2003;58(6 Suppl):S3-43. The canonical multi-disciplinary standard.
Convened in Paris (2002), this workshop aimed to unify the Japanese Research Society for Cancer terminology with Western endoscopic practice. It has since become the mandatory "alphabet" for describing any GI lesion in academic publications.
