In vivo histopathology using endocytoscopy for non-neoplastic changes in the gastric mucosa: a prospective pilot study (with video).

Background: Endocytoscopy (EC), as a novel ultrahigh magnification technology, enables in vivo histopathological diagnoses of the GI tract. EC is particularly exceptional when comparing dysplastic and neoplastic tissue with normal tissue. There are, however, no detailed data for minute or minimal changes in the gastric mucosa.

Objective: To describe non-neoplastic EC patterns of the gastric mucosa correlated with histopathological findings and to determine any relationship with Helicobacter pylori (HP) infection.

Design: A pilot prospective study.

Setting: Tertiary care referral center.

Patients: Sixty-four participants undergoing upper endoscopy for various indications.

Methods: Antral mucosal patterns on EC were divided into 4 categories: type 1 (normal), each papilla/pit has round smooth structure; type 2 (gastritis), extended, notched, and distorted structure with some necrotic tissue; type 3(atrophy), neighboring papilla/pit take on a lobulated appearance; type 4 (intestinal metaplasia [IM]), goblet cells are identified in a completely stained crypt. Target biopsy specimens were obtained from the region identified with these patterns, and multiple HP tests were performed.

Results: HP positivity was 0%, 40.9%, 50.0%, and 58.3% in types 1, 2, 3, and 4, respectively. The sensitivity and specificity of types 2+3+4 for HP positivity were 100％ and 42.5%, respectively. The positive predictive values of type 1 for normal, type 2 for chronic gastritis, type 3 for atrophic gastritis, and type 4 for IM were 100%, 62.5%, 40.0%, and 100%, respectively. The sensitivity and specificity of types 3+4 for atrophic gastritis to IM were 87.0% and 95.1%, respectively.

Limitations: Small, single-center, pilot study.

Conclusions: EC can differentiate gastric mucosal patterns of minimal, non-neoplastic change and appears to reliably exclude HP infection.