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

Background: Submucosal 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. Objective: To devise and validate an index based on these criteria (smooth, protruding lesion index on capsule endoscopy [SPICE]) to discriminate SMMs from innocent bulges. Design: Single-center, prospective study. Setting: General hospital in Busto Arsizio, Italy. Patients: This study involved 25 of 424 consecutive SBCEs performed on as many patients having SBCE findings of smooth, round, protruding lesions. Intervention: Patients' 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 Measurements: SPICE accuracy, using the final diagnosis of each patient as the criterion standard. Results: Six 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. Limitations: Single-center study; small sample size; no invasive ascertainment in 36% of patients. Conclusion: SPICE is easy to calculate and useful for distinguishing SMMs from innocent bulges. An index >2 is predictive of SMM. (Gastrointest Endosc 2011;74:1067-74.)