During endoscopic surveillance of a 58-year-old man with Barrett esophagus, the endoscopist documents salmon-pink columnar mucosa extending 4 cm circumferentially above the gastroesophageal junction, with maximum tongues extending 6 cm. Using the Prague C&M classification as marked **D** in the diagram, which of the following best describes the extent of this patient's Barrett segment and its clinical significance?

Explanation

## Why C4M6 — long-segment Barrett with higher cancer risk, requiring more intensive surveillance and consideration of endoscopic eradication therapy is right The Prague C&M classification quantifies Barrett esophagus extent by measuring the circumferential length (C) and maximum tongues (M) of columnar mucosa above the gastroesophageal junction. In this case, 4 cm circumferential + 6 cm maximum tongues = C4M6. According to Harrison 21e and AGA 2022 guidelines, long-segment Barrett (≥3 cm) carries higher neoplastic risk than short-segment disease. The C4M6 classification places this patient in the long-segment category, which mandates more intensive surveillance protocols and consideration of endoscopic eradication therapy (RFA or EMR) rather than surveillance alone, particularly if dysplasia is detected on biopsy. ## Why each distractor is wrong - **C2M4 — short-segment Barrett with lower cancer risk, requiring surveillance every 5 years**: The measurements given (4 cm circumferential, 6 cm tongues) do not correspond to C2M4. This option misrepresents both the Prague classification values and incorrectly classifies the segment as short-segment (which is <3 cm circumferential). - **C3M5 — intermediate-segment Barrett with moderate cancer risk, requiring surveillance every 3 years**: While C3M5 is closer to the actual measurements, it underestimates the circumferential extent (4 cm, not 3 cm). The Prague classification is precise; misreporting the C value leads to incorrect risk stratification and surveillance intervals. - **C6M4 — extensive Barrett with very high cancer risk, requiring immediate esophagectomy**: This option reverses the C and M values (C6 instead of C4) and incorrectly recommends esophagectomy. Esophagectomy is reserved for invasive adenocarcinoma (T1b or higher), not for non-dysplastic or dysplastic Barrett esophagus, which is managed with endoscopic eradication therapy per current AGA guidelines. **High-Yield:** Prague C&M classification: C = circumferential length, M = maximal tongues; long-segment (≥3 cm) Barrett requires intensive surveillance and consideration of endoscopic eradication therapy; short-segment (<3 cm) may be surveilled every 5 years if non-dysplastic. [cite: Harrison 21e Ch 322; AGA Guidelines 2022]