Screening for precancerous lesions of upper gastrointestinal tract: from the endoscopists' viewpoint

Abstract

Upper gastrointestinal tract cancers are one of the most important leading causes of cancer death worldwide. Diagnosis at late stages always brings about poor outcome of these malignancies. The early detection of precancerous or early cancerous lesions of gastrointestinal tract is therefore of utmost importance to improve the overall outcome and maintain a good quality of life of patients. The desire of endoscopists to visualize the invisibles under conventional white-light endoscopy has accelerated the advancements in endoscopy technologies. Nowadays, image-enhanced endoscopy which utilizes optical- or dye-based contrasting techniques has been widely applied in endoscopic screening program of gastrointestinal tract malignancies. These contrasting endoscopic technologies not only improve the visualization of early foci missed by conventional endoscopy, but also gain the insight of histopathology and tumor invasiveness, that is so-called optical biopsy. Here, we will review the application of advanced endoscopy technique in screening program of upper gastrointestinal tract cancers.

Figure 1

(a) Magnifying endoscopy under white-light imaging shows microvasculature of the normal esophagus. (b) Magnifying endoscopy under narrow-band imaging improves visualization of the reddish-brown superficial vessels (white arrow, Inoue's classification of intraepithelial papillary capillary loops type II) and the cyanic hue deeper vessels (black arrow).

Figure 2

By adjusting a switchover apparatus (white arrow), the magnifying endoscope (GIF-H260Z, Olympus Medical Systems Corp, Tokyo, Japan) with plastic cap-fitted at its end (black arrow) can provide 80-fold zooming images.

Figure 3

(a) Conventional white-light imaging endoscopy shows a type 0-IIc hyperemic lesion of esophagus. (b) Magnifying endoscopy with narrow-band imaging system reveals abnormal intraepithelial papillary capillary loops (Inoue's classification type IV to V₃). (c) and (d) Chromoendoscopy with 1.5% Lugol's solution discloses Lugol-unstained area which appears pinkish under white-light imaging and silver pattern under narrow-band imaging 3 minutes after spraying dyes.

Figure 4

(a) White-light imaging endoscopy shows Barrett's esophagus. (b) Chromoendoscopy with 2% acetic acid shows “acetowhitening” reaction of the mucosa with intestinal metaplasia. (c) Magnifying endoscopy with narrow-band imaging system reveals nondysplastic mucosa presenting cerebriform or gyri-like pit pattern with superficial blood vessels regularly situated between the mucosal ridges. (d) Magnifying endoscopy with white-light imaging shows increased vascularity of mucosa breaks which appears as a villous pit pattern (e) after acetic acid spraying. (f) Magnifying endoscopy under narrow-band imaging system disclosed low-grade dysplasia with irregular/disrupted mucosal patterns and irregular vascular patterns.

Figure 5

Inoue's classification of intraepithelial papillary capillary loops for esophageal neoplasia.

Figure 6

(a) White-light imaging endoscopy shows a type 0-IIb lesion with mildly hyperemic change of mucosal surface. (b) Chromoendoscopy after spraying 1.5% Lugol's solution discloses Lugol-unstained appearance. (c) Magnifying endoscopy with narrow-band imaging system reveals abnormal superficial vessels (Inoue's classification of intraepithelial papillary capillary loops type V).

Figure 7

(a) Conventional endoscopy shows an esophageal circumferential long-segment neoplasia with hyperemic changes and nodularity of surface mucosa which turns to brownish discoloration (b) under narrow-band imaging system. (c) Under magnification with narrow-band imaging, abnormal superficial vessels are well demonstrated (Inoue's classification type V_N). (d) Chromoendoscopy with 1.5% Lugol's solution shows extended Lugol-voiding area.

Figure 8

(a) Conventional white-light imaging endoscopy shows an ulcerative mass with lumen obstruction of the esophagus. (b) i-scan (SE 6+, CE 4+, TE-e) discloses reddish discoloration of the adjacent mucosa which is Lugol unstained (c), and the pathology is high-grade intraepithelial neoplasia.

Figure 9

Magnifying endoscopy with narrow-band imaging of intestinal metaplasia change of gastric mucosa shows light blue crest sign (a fine, blue-white line on the crests of the epithelial surface).