Comprehensive imaging of gastroesophageal biopsy samples by spectrally encoded confocal microscopy

Background

Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal microscopy technique that has the potential to be used for acquiring comprehensive images of the entire distal esophagus endoscopically with subcellular resolution.

Objective

The goal of this study was to demonstrate large-area SECM in upper GI tissues and to determine whether the images contain microstructural information that is useful for pathologic diagnosis.

Design

A feasibility study.

Setting

Gastrointestinal Unit, Massachusetts General Hospital.

Patients

Fifty biopsy samples from 36 patients undergoing routine EGD were imaged by SECM, in their entirety, immediately after their removal.

Results

The microstructure seen in the SECM images was similar to that seen by histopathology. Gastric cardia mucosa was clearly differentiated from squamous mucosa. Gastric fundic/body type mucosa showed more tightly packed glands than gastric cardia mucosa. Fundic gland polyps showed cystically dilated glands lined with cuboidal epithelium. The presence of intraepithelial eosinophils was detected with the cells demonstrating a characteristic bilobed nucleus. Specialized intestinal metaplasia was identified by columnar epithelium and the presence of goblet cells. Barrett's esophagus (BE) with dysplasia was differentiated from specialized intestinal metaplasia by the loss of nuclear polarity and disorganized glandular architecture.

Limitations

Ex vivo, descriptive study.

Conclusions

Large-area SECM images of gastroesophageal biopsy samples enabled the visualization of both subcellular and architectural features of various upper GI mucosal types and were similar to the corresponding histopathologic slides. These results suggest that the development of an endoscopic SECM probe is merited.

Abbreviations: BE, Barrett's esophagus, H&E, hematoxylin and eosin, HGD, high-grade dysplasia, MGH, Massachusetts General Hospital, OFDI, optical frequency domain imaging, RCM, reflectance confocal microscopy, SECM, spectrally encoded confocal microscopy, SIM, specialized intestinal metaplasia