Characterization and identification of gastric hyperplastic polyps and adenomas by confocal laser endomicroscopy.

BACKGROUND: Management of gastric polyps depends on their histologic composition. A real-time in vivo histologic diagnosis would be valuable to an "on table" management decision. Confocal laser endomicroscopy (CLE), a new diagnostic tool, allows real-time in vivo histologic evaluations of gastrointestinal lesions. This study aimed to assess the feasibility and practicability of using CLE to identify and differentiate gastric hyperplastic polyps and adenomas. METHODS: A total of 66 patients with previously diagnosed polyps were recruited for this study between January 2007 and August 2008 at Qilu Hospital, Shandong University, China. The CLE imaging of hyperplastic polyps and adenomas was performed, and the CLE diagnosis was compared with the gold standard of histopathologic diagnosis. RESULTS: Imaging by CLE was successfully performed for 60 lesions of gastric hyperplastic polyps and 27 lesions of gastric adenomas. Compared with the surrounding background mucosa, gastric hyperplastic polyps and adenomas showed typical distinct appearances, respectively, by CLE. The overall accuracy of the in vivo CLE diagnosis of gastric hyperplastic polyps and adenomas during ongoing endoscopy was 90% (95% confidence interval [CI], 83-96%), and the overall accuracy of differentiating gastric hyperplastic polyps and adenomas by CLE was 97% (95% CI, 90-99%) after endoscopy. Intraobserver agreement was perfect (kappa = 0.92; 95% CI, 0.82-0.99), and interobserver agreement was also good (kappa = 0.83, 95% CI, 0.70-0.96). CONCLUSIONS: This study characterized confocal images of gastric hyperplastic polyps and adenomas as well as the high accuracy of differentiating hyperplastic polyps and adenomas using CLE.

Confocal endomicroscopy for in vivo detection of microvascular architecture in normal and malignant lesions of upper gastrointestinal tract.

BACKGROUND AND AIM: Confocal laser endomicroscopy allows subsurface analysis of gastrointestinal mucosa during ongoing endoscopy. The present study assessed the feasibility of in vivo detecting superficial vascular architecture by confocal endomicroscopy in normal upper gastrointestinal mucosa and malignant lesions. METHODS: Early gastric cancer in eight patients, superficial esophageal carcinoma in six patients, and asymptomatic normal control in 10 patients were studied by confocal endomicroscopy. The characteristic of endomicroscopic microvascular architecture from normal and malignant mucosa was described and images were evaluated. RESULTS: Confocal endomicroscopy enabled clear visualization of the vascular networks of gastroesophageal mucosa. Honeycomb-like and coil-shaped regular microvascular architecture surrounding gastric pits were visible in the normal gastric body and antrum, respectively. Differentiated gastric cancerous mucosa showed hypervascularity and various caliber microvessels with irregular shapes. Undifferentiated gastric cancers disclosed a hypovascularity and irregular short branch vessels. Normal squamous epithelium had regular intraepithelial papillary capillary loops (IPCLs) directed toward the luminal surface. In superficial esophageal squamous carcinoma, dilated IPCLs were visible at the upper layer of the squamous mucosa. In esophageal adenocarcinoma, abnormal microvascular architecture showed tortuous and various calibers blood vessels. Of all the images, 41% were graded as good quality. The mean kappa value for interobserver agreement for the prediction of cancerous mucosa was 0.792. CONCLUSIONS: Confocal laser endomicroscopy system could yield very clear images of superficial microvascular network in the gastroesophageal mucosal layer both in malignant and normal mucosa. Endomicroscopic observation of vascular architecture may be of assistance in the identification of early gastroesophageal cancers.

[Vasculogenic mimicry in the bi-directional differentiation malignant tumors of digestive tract].

OBJECTIVE: To investigate whether vasculogenic mimicry (VM) exists in the bi-directional differentiation malignant tumors of digestive tract. METHODS: 111 specimens of bi-directional differentiation malignant tumors of digestive tract. including malignant gastrointestinal stromal tumors (GIST, n = 80), malignant melanoma (n = 18), and carcinosarcoma (n = 13), underwent periodic acid Schiff (PAS) staining and microscopy. Immunohistochemistry was used to examine the expression of vascular endothelial growth factor (VEGF), and CD31. Microvascular density (MVD) and vasculogenic mimicry density (VMD) were calculated. RESULTS: PAS-positive patterned matrix-associated vascular channels with red blood cells therein were detected in 39.1% (31.5/111) of the tumor samples. (89 +/- 20) and MVD (47 +/- 12) both lower than without VM (76, 126 +/- 18, 78 +/- 13, all P < 0.05) the expression levels of VEGF and MVD in the tumors containing patterned channels were (89 +/- 20) and MVD (47 +/- 12) respectively, both significantly lower than those in the tumors without VM [(126 +/- 18) and (78 +/- 13) respectively, both P < 0. 05]. The higher the malignant degree of tumor, the higher the proportion of the tumor with VM. The levels of MVD and VMD of the GIST, malignant melanoma, and carcinosarcoma with low malignancy were 45 +/- 19, 15 +/- 8, and 38 +/- 25 respectively, all significantly lower than those of the GIST, malignant melanoma, and carcinosarcoma with high malignancy (128 +/- 42, 81 +/- 17, 122 +/- 39, all P < 0.05). CONCLUSION: VM exists in the bi-directional differentiation malignant tumors of digestive tract. The tumor cells obtain blood supply and become metastatic via the mechanism of VM.

Classification of gastric pit patterns by confocal endomicroscopy.

BACKGROUND: Confocal endomicroscopy is a newly developed endoscopic imaging technology that produces 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 underwent 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.