Enter the axial measurements in centimeters to generate the standardized Prague C & M reporting metric.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Standardized reporting of the endoscopic extent of Barrett's Oesophagus (BE)
Measuring the response to endoscopic therapies (e.g., Radiofrequency Ablation)
Research-grade longitudinal tracking of segment regression or progression
Anatomical Landmarks
The Barrett's segment is measured relative to the gastro-oesophageal junction (GOJ), which is endoscopically defined as the proximal extent of the gastric folds.
Section 2
Formula & Logic
The C & M Components
01
C (Circumferential): Depth of the circumferential columnar lining above the GOJ (in cm).
02
M (Maximum): Depth of the longest tongue of columnar lining above the GOJ (in cm).
Reporting Format
The score is reported as "C[x] M[y]." For example, C2 M5 indicates a 2cm circumferential segment with a 5cm maximum tongue.
Minimum Requirement
The Prague criteria should only be applied if there is ≥ 1 cm of columnar lining. For segments < 1 cm, report as "Short Segment BE" or "Irregular Z-line."
Section 3
Pearls/Pitfalls
Risk of Neoplasia
The risk of progression to Oesophageal Adenocarcinoma (OAC) is proportional to the length of the Barrett's segment. Segments > 3 cm (Long-segment BE) carry a higher risk than segments < 3 cm (Short-segment BE). The Maximum (M) length is often the most critical prognostic marker.
Inter-observer Reliability
The Prague criteria were specifically designed to overcome the subjectivity of simply saying "Long" or "Short." It has an extremely high intraclass correlation ($>0.9$) for segments over 1 cm.
Clinical Pearls
Always measure on scope withdrawal to avoid anatomical distortion from over-insufflation
Hiatal hernia must be documented separately to avoid confusing the hiatus with the GOJ
Islands of columnar mucosa (scattered above the M extent) should be noted but are not included in the C/M measurements
Section 4
Next Steps
Surveillance Intervals (ACG)
01
Confirmed Barrett's (with IM): Surveillance every 3–5 years depending on length.
02
Barrett's with Dysplasia: Escalation to endoscopic eradication (RFA/EMR).
Complementary Scoring
Paris Classification (Morphology)
Vienna Classification (Histology)
Siewert Classification (Location)
Section 5
Evidence Appraisal
The Definitive Paper
The development and validation of an endoscopic classification system for Barrett's esophagus: the Prague C & M criteria.
Sharma P et al. • Gastroenterology. 2006;131(5):1392-9. The primary description and global validation study.
Developed by an international group of esophagologists at a workshop in Prague. It aimed to unify the "tongue" vs. "circumference" debate into a single standardized measurement tool that every doctor could use without special training.
