Gastroenterology: Simultaneous practice of narrow band imaging and confocal laser endomicroscopy for a case of early duodenal cancer

Development of a new classification for in vivo diagnosis of duodenal epithelial tumors with confocal laser endomicroscopy: A pilot study

BACKGROUND AND AIM

Confocal laser endomicroscopy (CLE) has been established for in vivo diagnosis of various gastrointestinal diseases. However, validated criteria for confocal diagnosis of duodenal tumors do not exist. Therefore, the aim of the present pilot study was to develop a novel classification for in vivo optical diagnosis of duodenal tumors using CLE.

METHODS

Consecutive patients with duodenal tumorous lesions were included. First, an initial classification system was developed which was then validated. Histopathology was used as a reference standard.

RESULTS

A simple classification system for in vivo diagnosis of duodenal epithelial tumors using CLE was developed. Sensitivity, specificity, and accuracy were 90%, 100%, and 97%, respectively. Positive and negative predictive values were calculated as 100% and 96%. The kappa coefficient representing consistency was 1 between observers and within each observer.

CONCLUSION

A new classification for in vivo diagnosis of duodenal epithelial tumors using confocal imaging has been developed. The new classification system allows adequate prediction of histology and could therefore be used to guide subsequent therapy of duodenal lesions.

Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach

Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pCLE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein.