Development of a novel index to discriminate bulge from mass on small-bowel capsule endoscopy

BackgroundSubmucosal malignant masses (SMMs) and innocent bulges look similar on small-bowel capsule endoscopy (SBCE). In a previous observational study, 4 criteria associated with innocent bulges were recognized.ObjectiveTo devise and validate an index based on these criteria (smooth, protruding lesion index on capsule endoscopy [SPICE]) to discriminate SMMs from innocent bulges.DesignSingle-center, prospective study.SettingGeneral hospital in Busto Arsizio, Italy.PatientsThis study involved 25 of 424 consecutive SBCEs performed on as many patients having SBCE findings of smooth, round, protruding lesions.InterventionPatients' evaluation up to the final diagnosis. At study entry, a short video clip of the lesion was obtained and deidentified for blind SPICE calculation.Main Outcome MeasurementsSPICE accuracy, using the final diagnosis of each patient as the criterion standard.ResultsSix patients had SMMs (4 GI stromal tumors, 2 neuroendocrine tumors), and 19 had innocent bulges. SPICE scores ranged from 0 to 4; they discriminated SMMs from innocent bulges (P = .002). A SPICE value >2 had 83.3% sensitivity and 89.4% specificity, and the area under the curve was 0.90 (95% confidence interval, 0.72-0.98; P < .001) for the detection of SMMs.LimitationsSingle-center study; small sample size; no invasive ascertainment in 36% of patients.ConclusionSPICE is easy to calculate and useful for distinguishing SMMs from innocent bulges. An index >2 is predictive of SMM.