The Sydney System can be used to accurately describe the extent and histologic appearance of gastritis. The scheme was developed by a Working Party designated at the 9th World Congresses in Gastroenterology.



(1) etiology (prefix term)

(2) topography and special forms/associations (core term)

(3) morphology (suffix term)


Etiological classification:

(1) Helicobacter pylori

(2) autoimmune-associated

(3) idiopathic

(4) drug-associated

(5) other gastric irritant

(6) bacterial, other than Helicobacter

(7) viral

(8) parasitic

(9) fungal



(1) corpus

(2) antrum

(3) both corpus and antrum (pangastritis)



(1) acute (acute inflammation with no or minimal chronic inflammation)

(2) chronic (lymphoplasmocytic predominant)

(3) special forms (with a recognizable pattern)


Special forms:

(1) eosinophilic gastritis

(2) lymphocytic gastritis

(3) Crohn's disease associated granulomatous gastritis

(4) sarcoidosis

(5) idiopathic granulomatous gastritis

(6) reactive gastritis

(7) radiation-associated gastritis

(8) phlegmonous gastritis

(9) post-gastrectomy associated


Morphological parameters determined separately for the corpus and antrum:

(1) chronic inflammation

(2) activity (acute neutrophilic infiltrate)

(3) atrophy

(4) intestinal metaplasia

(5) number of bacteria morphologically consistent with Helicobacter pylori


Grading for each morphologic parameter:

(1) none

(2) mild

(3) moderate

(4) severe


Additional non-graded variables:

(1) nonspecific

(2) specific


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