# A Three‐Way Comparison of Nodular Lesions in H. pylori‐Induced Gastritis, Non‐Helicobacter pylori Helicobacter (NHPH)‐Induced Gastritis, and NHPH‐Induced MALT Lymphoma Reveals Their Distinct Endoscopic Predictors: Distribution for Bacterial Etiology and Morphology for Malignancy

## TL;DR

This study compares endoscopic features of three types of nodular gastritis to distinguish between benign and malignant cases and different Helicobacter species.

## Contribution

The study identifies specific endoscopic predictors for bacterial etiology and malignancy in nodular gastritis.

## Key findings

- Morphological features of nodules reflect the presence or absence of malignancy.
- Distributional features are associated with the underlying Helicobacter species.
- Combining endoscopic features achieves high diagnostic accuracy between the three conditions.

## Abstract

Nodular gastritis associated with
Helicobacter pylori
infection (HPi‐NG) has long been recognized. Recently, similar mucosal changes have been reported with non‐
H. pylori Helicobacter (NHPH), including NHPH‐induced gastric mucosa‐associated lymphoid tissue lymphoma with a nodular gastritis‐like appearance (NHPHi‐MNG) and NHPH‐induced nodular gastritis (NHPHi‐NG). However, how bacterial species differences and the presence or absence of malignancy are reflected in endoscopic appearance has not been sufficiently investigated. This study aimed to clarify these relationships and to identify key endoscopic features that differentiate among the three clinically distinct entities.

We retrospectively analyzed 69 patients diagnosed at Hiroshima University Hospital between 2013 and 2024: 11 with NHPHi‐MNG, 12 with NHPHi‐NG, and 46 with HPi‐NG. Endoscopic findings were compared, focusing on three morphological features of the nodules (maximum diameter, size heterogeneity, and shape) and three distributional features (extent of nodularity, extension to the lower gastric body, and predominant site of nodularity), along with patient sex. Diagnostic accuracy was calculated based on combinations of these features.

NHPHi‐MNG was differentiated from NHPHi‐NG with 91.3% accuracy when two or more of the three morphological criteria were satisfied. NHPHi‐MNG was distinguished from HPi‐NG with 93.0% accuracy when four or more of seven criteria were fulfilled: the three morphological features, three distributional features, and patient sex. NHPHi‐NG was differentiated from HPi‐NG with 91.4% accuracy when all three distributional features were present.

Among the three nodular gastric conditions, the morphological features of nodules reflected the presence or absence of malignancy, whereas the distributional features were associated with the underlying bacterial species. These findings suggest that specific endoscopic features can aid in distinguishing between benign and malignant forms of nodular gastric lesions and between infections with different Helicobacter species, providing important diagnostic guidance.