In vivo histopathology for detection of gastrointestinal neoplasia with a portable, confocal miniprobe: an examiner blinded analysis.

BACKGROUND & AIMS: Confocal fluorescence microscopy (CFM) has been mentioned to be a promising tool for in vivo histology. Recently, a portable confocal miniprobe has been developed. Our aim was to evaluate the potential benefit of CFM for detection of gastrointestinal neoplasia. METHODS: A total of 47 patients with known or suspected neoplasia in the upper (n = 34) or lower gastrointestinal tract (n = 13) were examined with standard endoscopes. After mucolyis with 5-10 mL of acetic acid 1.5%, chromoendoscopy with 2-5 mL cresyl violet 0.25% was performed, with the substance also being used as a fluorophore for CFM. Real-time video sequences were recorded. Thereafter, biopsies were taken or mucosectomy/polypectomy was performed from the same examined area. All stored sequences were put into a random order and assessed by a pathologist and a gastroenterologist both blinded to any data. RESULTS: A total of 119 CFM video sequences were recorded of 85 benign or 34 neoplastic areas. Quality of CFM images was regarded too low in 24 (pathologist) and 14 sequences (gastroenterologist). For the pathologist, accuracy of CFM detecting neoplasia was 92.6% (suitable images) and 73.9% (intention to diagnose). The respective accuracy values for the gastroenterologist were 92.4% (suitable images) and 81.5% (intention to diagnose). Agreement between CFM and histopathology was excellent (kappa values, 0.821 and 0.817). CONCLUSIONS: We have demonstrated that CFM with a miniprobe has the potential to diagnose neoplasia during ongoing endoscopy. This system has the advantage that it can be used with standard endoscopes. Further studies are warranted for validation.

In vivo imaging of the bronchial wall microstructure using fibered confocal fluorescence microscopy.

RATIONALE: Fibered confocal fluorescence microscopy (FCFM) is a new technique that produces microscopic imaging of a living tissue through a 1-mm fiberoptic probe that can be introduced into the working channel of the bronchoscope. OBJECTIVES: To analyze the microscopic autofluorescence structure of normal and pathologic bronchial mucosae using FCFM during bronchoscopy. METHODS: Bronchial FCFM and spectral analyses were performed at 488-nm excitation wavelength on two bronchial specimens ex vivo and in 29 individuals at high risk for lung cancer in vivo. Biopsies of in vivo FCFM-imaged areas were performed using autofluorescence bronchoscopy. RESULTS: Ex vivo and in vivo microscopic and spectral analyses showed that the FCFM signal mainly originates from the elastin component of the basement membrane zone. Five distinct reproducible microscopic patterns were recognized in the normal areas from the trachea down to the more distal respiratory bronchi. In areas of the proximal airways not previously biopsied, one of these patterns was found in 30 of 30 normal epithelia, whereas alterations of the autofluorescence microstructure were observed in 19 of 22 metaplastic or dysplastic samples, five of five carcinomas in situ, and two of two invasive lesions. Disorganization of the fibered network could be found on 9 of 27 preinvasive lesions, compatible with early disruptions of the basement membrane zone. FCFM alterations were also observed in a tracheobronchomegaly syndrome and in a sarcoidosis case. CONCLUSIONS: Endoscopic FCFM represents a minimally invasive method to study specific basement membrane alterations associated with premalignant bronchial lesions in vivo. The technique may also be useful to study the bronchial wall remodeling in nonmalignant chronic bronchial diseases.

Evaluation of the interobserver reproducibility of Gleason grading of prostatic adenocarcinoma using tissue microarrays.

The Gleason system is the internationally recognized standard for grading prostate cancer, due mainly to its strong prognostic capability. However, interobserver reproducibility is variable in the community setting. Herein we present a novel approach to evaluating Gleason grading among pathologists using high-density tissue microarrays (TMAs). A CD-ROM containing 537 different TMA spot images of 0.6-mm diameter was sent to 10 genitourinary pathologists in France. The pathologists were expected to score each TMA spot based on their experience evaluating standard prostate biopsies, transurethral resections, and prostatectomy samples. There was no consensus meeting beforehand to agree on how the group would apply the Gleason grading system for this project. Percentage of agreement and kappa value were used to assess the level of agreement. A short questionnaire was sent to assess pathologists' opinion on this new approach to evaluating Gleason grading. An average of 311 images were analyzed (range, 104 to 537; median, 256.5). Four of the pathologists evaluated all 537 images and assigned Gleason grades to 149 images with an overall kappa for interobserver agreement for the exact score between 0.31 and 0.52 and between 0.45 to 0.69 if 3 Gleason categories (7) were used. When 2 categories were considered (7), kappa ranged from 0.58 to 0.83. All pathologists analyzed 104 images. Similar results were obtained with an agreement between 0.28 and 0.54 for the 3 Gleason categories. After finishing this test, 90% of genitourinary pathologists considered this approach useful for resident training and 90% for pathology teaching. We conclude that a Gleason score can be easily assigned to each TMA spot of a 0.6-mm-diameter prostate cancer sample. These data also indicated that using TMA spot images may be a good approach for teaching the Gleason grading system due to the small area of tissue.