Endocytoscopy: technology and clinical application in upper gastrointestinal tract

Abstract

Over the past few years, the innovative field of magnifying endoscopy has been expanding with various cutting-edge technologies, one of which is endocytoscopy, to facilitate improvement in the detection and diagnosis of gastrointestinal lesions. Endocytoscopy is a novel ultra-high magnification endoscopic technique enabling high-quality in-vivo assessment of lesions found in the gastrointestinal tract with the use of intraprocedural stains. The main scope of this review article is to offer a closer look at the latest endocytoscopic technology and its clinical application in the upper gastrointestinal tract, especially in the esophagus and stomach, as well as to introduce readers to our simplified and up-to-date endocytoscopic classification, specifically developed for the esophagus and stomach, for the in-vivo assessment and diagnosis of esophageal and gastric lesions. Despite the good accuracy of endocytoscopy in the diagnosis of esophageal and gastric lesions in recent studies, some challenges still remain (e.g., staining method and standardized endocytoscopic classification). Through continuous evaluation and improvement of methods and skills, these challenges may be overcome thus establishing current techniques and classification, paving the way for further advances in the field of endocytoscopy and magnifying endoscopy. In all, endocytoscopy seems to aid in the in-vivo diagnosis of gastrointestinal tract lesions and may, in the future, revolutionize the field of in-vivo endoscopic diagnosis of gastrointestinal cancer, representing another step towards the so-called optical biopsy.

Keywords: Endocytoscopy (EC); diagnosis; endoscopy; ultra-high magnification endoscopy.

Figure 1

CM double staining: (A) 10 cc of 0.05% crystal violet and 1 cc of 1% methylene blue is mixed in a 10 cc syringe (red arrow), and 1 cc of this mixture is aspirated in several different 10 cc syringes with 9 cc of air (yellow arrows). (B) Spraying of the CM mixture is done several times through the scope channel with an interval of 15 to 30 seconds until a satisfactory staining is achieved.

Figure 2

Esophageal EC classification: representative pictures differentiating EC1a (normal), EC1b (esophagitis), EC2 (intraepithelial neoplasia), and EC3 (squamous cell carcinoma). EC1a shows regularly arranged large rhomboid-shaped cells. EC1b shows blunted edges and more rounded cells. EC2 shows an increase in cellular density but still with a recognizable cell structure. EC3 shows complete loss of cellular structure with a significant increase in cellular density.

Figure 3

Gastric EC classification: representative pictures differentiating EC1 (non-neoplasia), EC2 (adenoma), and EC3 (cancer). EC1 shows regularly arranged glands with consistent pattern and preserved lumen. EC2 shows narrowing of the lumen and a more compact arrangement of glands. EC3 shows complete distortion of glandular structure and significant swelling of the nuclei (enlarged nuclear sign).

Figure 4

“Enlarged nuclear sign”: representative pictures of the “enlarged nuclear sign” (yellow arrows) by endocytoscopy (A) and by histopathology (B). Hyperchromasia and significant swelling of the nucleus is observed along with “taking over” of the cell surface.