Morphology‐Based Cytosponge Cytology Versus Concurrent Endoscopic Biopsy for Detecting Dysplasia in Barrett's Oesophagus Surveillance: A Prospective, Single‐Centre Paired Study

BACKGROUND: Barrett's oesophagus (BE) is the principal precursor of oesophageal adenocarcinoma, and guidelines recommend endoscopic surveillance to detect dysplasia. Endoscopy is invasive and resource-intensive. The Cytosponge is a non-endoscopic cell-collection device. We evaluated Cytosponge cytology against concurrent endoscopic biopsy for detecting dysplasia in a BE surveillance population, and explored factors associated with sample adequacy. METHODS: In this prospective, single-centre study, patients with established BE underwent a Cytosponge procedure with a concurrent same-visit endoscopic biopsy. Cytosponge cell blocks were stained with H&E and Alcian Blue 2.5/Periodic Acid-Schiff. Two blinded gastrointestinal pathologists recorded goblet cells and dysplasia by consensus. Sensitivity, specificity, and predictive values with 95% confidence intervals (CI) were calculated against biopsy, and age-adequacy association tested with Fisher's exact test. RESULTS: Fifty-nine participants were analyzed (median age 70 years; 93.2% male). Cytosponge samples were adequate in 46/59 (78.0%; 95% CI 65.9-86.6). Among 44 adequate paired samples, sensitivity for dysplasia was 76.5% (95% CI 52.7-90.4), specificity 92.6% (76.6-97.9), positive predictive value 86.7%, and negative predictive value 86.2%. Sensitivity for definite (low- plus high-grade) dysplasia was 85.7% (12/14); the lower overall figure reflected indefinite-for-dysplasia cases, of which only one of three was detected. Inadequacy was higher in patients aged ≥ 71 than ≤ 70 years (30% vs. 16%; p = 0.22). No procedural complications occurred. CONCLUSIONS: Cytosponge cytology showed high specificity and moderate sensitivity for dysplasia, with a positive result strongly predicting biopsy-confirmed dysplasia. These pilot data support further evaluation of Cytosponge cytology, reported by trained pathologists, as a non-endoscopic triage tool in BE surveillance.