Classification of gastric pit patterns by confocal endomicroscopy

Background: Confocal endomicroscopy is a newly developed endoscopic imaging technology that produce 1000-fold magnification cross-sectional images of the GI surface and subsurface tissue during routine endoscopy. The gastric pit patterns identified by confocal endomicroscopy and correlation with histopathologic examination have not yet been established. Objective: Our purpose was to explore the appearance of various kinds of gastric pits and clarify the relationship between gastric pit patterns and the histopathologic findings. Design: Descriptive study. Setting: Qilu Hospital, Shandong University, Jinan, China. Patients: A total of 132 consecutive patients under-went confocal endomicroscopy after 7 healthy volunteers had been examined in vivo and 10 samples resected from 10 patients with gastric cancer had been examined ex vivo by use of confocal endomicroscopy The confocal images obtained from the 132 patients were compared with the histopathologic findings of the biopsy specimens from the corresponding confocal imaging sites in a prospective and blinded fashion. Main Outcome Measurements: The relationship between the pit patterns and the histopathologic findings. Results: Gastric pit patterns were classified into 7 types. Normal mucosa with fundic glands mainly showed type A (round pits), and corporal mucosa with histologic gastritis showed type B (noncontinuous short rod-like); normal mucosa with pyloric glands mainly showed type C (continuous short rod-like), and antral mucosa with histologic gastritis showed type D (elongated and tortuous branch-like). Goblet cells were easily distinguished by confocal endomicroscopy in intestinal metaplasia mucosa, which showed type F. The sensitivity and specificity of the type E pattern for predicting gastric atrophy were 83.6% and 99.6%, respectively Corresponding values of the type G pattern for predicting gastric cancer were 90.0% and 99.4%. Limitations: No data on interobserver and intraobserver variability. Conclusions: The patterns of gastric pits identified by confocal endomicroscopy correlate well with the histopathologic findings. Confocal endomicroscopy may prove useful in predicting histopathologic diagnoses during routine endoscopic procedures.