Recent advancement of observing living cells in the esophagus using CM double staining: Endocytoscopic atypia classification

Abstract

Magnification endoscopy enables in vivo evaluation of gastrointestinal mucosa. Furthermore, endocytoscopy (ECS) with ultra-high magnification enables in vivo observation of cellular atypia during routine endoscopic examination. The purpose of this study is to clarify the efficacy of ECS and endocytoscopic atypia (ECA) classification in various types of benign and malignant pathology in the esophagus. Consecutive 110 patients, who underwent ECS in our institution from March 2003 to December 2009, were included in this study. One hundred and forty-six esophageal lesions were classified according to ECA classification, and these endocytoscopic images were compared with histological images. We categorized endocytoscopic images into five categories according to size and uniformity of nuclei, number of cells and regularity of cellular arrangement. Eighty-one out of 89 ECA-1 to ECA-3 lesions (91.0%) corresponded to Vienna categories 1 to 3. Seventy-one out of 84 ECA-4 or ECA-5 lesions (91.2%) corresponded to Vienna category 4 or 5. Overall accuracy of ECS was 91.3%, providing images similar to conventional hematoxylin and eosin staining. In addition, with ECS, we can take an 'optical biopsy' even in patients with cardiovascular disease without interrupting anticoagulant therapy. A newly designed single charge-coupled device endocytoscope allows observation of target tissue noninvasibly from regular magnification to ultra-high magnification. The development of ECS has opened the door to in vivo cellular imaging, enabling endoscopic diagnosis of tissue cytological atypia during routine endoscopic examination.

Endocytoscopic visualization of squamous cell islands within Barrett’s epithelium

“…Methylene blue or toluidine blue single staining was initially used for endocytoscopic evaluation of esophageal lesions [6,10,11] . Recently, however double staining with a mixture of 0.05% crystal violet and 0.1% methylene blue (CM) has been also proposed during ECS [2,3] . Crystal violet alone effectively stains the cytoplasm, while methylene blue single staining dyes both nuclei and cytoplasm, revealing details of cell structure [11,12] .…”

“…The dual CCD prototype carries both conventional magnification (× 80) and ultra-high magnification (× 480) abilities, which can be easily interchanged by pushing a button on the endocytoscope [2,6] . The single CCD prototype endocytoscope (CIF-Y0002, EC2 Olympus) has only one lens that can consecutively increase the magnification power from the conventional magnification power to × 380 using a hand lever.…”

“…Not only structural atypia, but also cellular atypia, with observation of lumens and nuclei, is achieved by recent advances in ECS [5][6][7][8][9] . Two different integrated type endocytoscopes (GIF-Q260, Olympus Medical Systems Corp, Tokyo, Japan) have been recently developed [2,6] . The first is a dual charged couple device (CCD) integrated type (CIF-Y0001, EC1 Olympus, Tokyo, Japan) and the other is a single CCD integrated type (CIF-Y0002, EC2 Olympus).…”

“…The single CCD prototype endocytoscope (CIF-Y0002, EC2 Olympus) has only one lens that can consecutively increase the magnification power from the conventional magnification power to × 380 using a hand lever. The video processor (prototype, Olympus CV-260X) with a light source (Olympus CLV-260) allows narrow-band imaging (NBI) [2] . Methylene blue or toluidine blue single staining was initially used for endocytoscopic evaluation of esophageal lesions [6,10,11] .…”

“…Endocytoscopy (ECS) with ultra-high magnification (× 400-1100) represents the most recent innovation in endoscopic imaging, permitting in vivo cellular imaging of gastrointestinal (GI) mucosa and visualization of nuclear atypia in neoplastic lesions during routine endoscopic examination [1][2][3][4][5] . Not only structural atypia, but also cellular atypia, with observation of lumens and nuclei, is achieved by recent advances in ECS [5][6][7][8][9] .…”