Aim: To characterize small bowel (SB) tumors detected by capsule endoscopy (CE), and identify missed tumors.
Methods: The study included 145 consecutive patients in whom 150 CEs were performed. Following CE, the medical records of the study population were reviewed. Results of double- or single-balloon enteroscopy performed after CE and the results of surgery in all patients operated on were retrieved. The patients were contacted through telephone interviews or postal mail. In addition, the national cancer registry and the polish clinical gastrointestinal stromal tumor (GIST) Registry were searched to identify missed neoplasms.
Results: Indications for CE included overt and occult obscure gastrointestinal bleeding (n = 81, 53.7%), anemia (n = 19, 12.7%), malabsorption (n = 18, 12%), abnormal CB follow through (n = 9, 6%), abdominal pain (n = 7, 5%), celiac disease (n = 5, 3%), neuroendocrine tumor (n = 3, 2%), Crohn's disease (n = 2, < 2%), Peutz-Jeghers syndrome (n = 2, < 2%), other polyposes (n = 2, < 2%), and diarrhea (n = 2, < 2%). The capsule reached the colon in 115 (76.6%) examinations. In 150 investigations, CE identified 15 SB tumors (10%), 14 of which were operated on or treated endoscopically. Malignancies included metastatic melanoma (n = 1), adenocarcinoma (n = 2), and GIST (n = 3). Benign neoplasms included dysplastic Peutz-Jeghers polyps (n = 4). Non-neoplastic masses included venous malformation (n = 1), inflammatory tumors (n = 2), and a mass of unknown histology (n = 1). During the follow-up period, three additional SB tumors were found (2 GISTs and one mesenteric tumor of undefined nature). The National Cancer Registry and Polish Clinical GIST Registry revealed no additional SB neoplasms in the post-examination period (follow-up: range 4.2-102.5 mo, median 39 mo). The sensitivity of CE for tumor detection was 83.3%, and the negative predictive value was 97.6%. The specificity and positive predictive value were both 100%.
Conclusion: Neoplasms may be missed by CE, especially in the proximal SB. In overt obscure gastrointestinal bleeding, complementary endoscopic and/or radiologic diagnostic tests are indicated.
Keywords: Capsule endoscopy; Gastrointestinal bleeding; Gastrointestinal stromal tumor; Small bowel tumor; Tumor miss rate.