Purpose: The aim of this study is to assess the capability of endocytoscopy (ECS) in differentiating neoplastic from nonneoplastic lesions in the colorectum and to validate an ECS classification.
Methods: Patients with colorectal polypoid and nonpolypoid lesions < or =10 mm were prospectively included. ECS classification subgrouped nonneoplastic (EC 0) and neoplastic (EC 1-3) lesions. Lesions were observed at super-magnified view (450x) before endoscopic resection. Blinded pathological assessment was obtained.
Results: Fifty-two lesions were examined in 49 patients (17 polypoid and 35 nonpolypoid). Final pathological diagnosis was normal mucosa or hyperplastic polyp in ten cases, low-grade adenoma in 29, high-grade adenoma in 11, and submucosal invasive cancer in two cases. Positive predictive values of each EC group were 100%, 93.1%, 90.1%, and 100%, respectively. ECS diagnosis correlated completely with pathology in the differentiation between neoplastic and nonneoplastic lesions.
Conclusions: ECS enabled observation of colorectal lesion at a subcellular level in vivo. The classification of ECS images had a good correlation with the final pathological diagnosis. ECS was useful to differentiate between neoplastic and nonneoplastic lesions.