Diagnostic value of confocal laser endomicroscopy for colorectal tubular adenocarcinoma

Objective To establish diagnostic standards of colorectal tubular adenocarcinoma with confocal laser endomicroscopy（CLE）, and to evaluate its diagnostic value in vivo.Methods The confocal images of 12 cases, which were pathologically confirmed colorectal tubular adenocarcinoma（4 well differentiated, 4 moderately differentiated and 4 poorly differentiated）, were collected and analyzed to establish diagnostic standards of the disease with CLE.Then 49 lesions were prospectively evaluated based on CLE standards,which were compared to histopathology results.Results The sensitivity, specificity, accuracy, positive predictive value（PV ＋）and negative predictive value（PV -）of CLE in diagnosing tubular adenocarcinoma were 94.7%, 90.9%, 93.9%, 100% and 76.9%, respectively.The corresponding data of well differentiated adenocarcinoma were 100%, 83.3%, 88.9%, 85.7% and 87.0%, those of moderately differentiated adenocarcinoma were 86.7%, 90.5%, 86.1%, 86.7% and 90.5%, and those of poorly differentiated adenocarcinoma were 77.8%, 92.6%, 88.9%, 100% and 86.2%.Conclusion CLE is able to diagnose and grade colorectal tubular adenocarcinoma. Key words: Confocal microscopy; Adenocarcinoma; Diagnosis; Evaluation studies