lymphocytic gastritis

Digital case

 HPC:311 : Follicular gastritis and active chronic gastritis, non-atrophical, Helicobacter pylori-associated
 HPC:328 : Lymphocytic gastritis

Definition: Lymphocytic gastritis is a chronic gastritis characterized by lymphocytosis of foveolar and surface epithelium.

Lymphocytic gastritis affects 0.83% to 4.5% of individuals,mainly middle-aged and elderly men.

The disorder complicates various diseases, including celiac disease,
helicobacter pylori infections, Crohn disease, HIV infections, Menetrier disease, lymphocytic enterocolitis, inflammatory polyps, hypersensitivity reactions, autologous hematopoietic cell transplantation, ticlopidine use, lymphoma and esophageal carcinoma.

However, the change is most common in celiac disease and in patients with HP infections.

In approximately 20% of cases, the etiology is unknown.

Some patients develop ulcers or hypoproteinemia.

The stomach appears normal or it may present with thickened gastric folds, often with multiple discrete mucosal nodules, ulcers, erosions, or elevations measuring 3 to 10mm in diameter.

These are covered with mucus and have central umbilications surrounded by hyperemia, leading to the name "varioliform gastritis".

The mucosal elevations persist after the erosions heal, resembling sessile hyperplastic polyps. The disorder affects the entire stomach.

Somepatients develop hypertrophic lymphocytic gastritis.

Lymphocytic gastritis is characterized by an intraepithelial lymphocytosis with at least 25 lymphocytes/100 epithelial cellsand mild foveolar hyperplasia.

Usually the intra-epithelial lymphocytosis is obvious so that counting the number of lymphocytes present is seldom required.

The intraepithelial lymphocytes are small and round, sometimes surrounded by a clear halo.

They infiltrate the basal part of the surface epithelium and the gastric pits.

The process spares the deeper glands. The lymphocytosis may be patchy so that different biopsies may vary in the intensity of the intraepithelial lymphocytosis.

The intra-epithelial lymphocytosis may be greater in the antrum in celiac disease,whereas it is greater in the corpus in HP infections.

In patients with celiac disease, the number of gastric intraepithelial lymphocytes correlates with the histologic severity of small intestinal disease and gluten restriction results in a marked reduction in intraepithelial lymphocytes.

An intense lamina propria lymphoplasmacytic infiltrate may accompany the intraepithelial lymphocytosis.

The pits acquire a corrugated and dilated appearance and their lumina may contain abundant mucus admixed with neutrophils forming pit abscesses.

Neutrophils are usually not present unless there are ulcers or erosions.

Foveolar hyperplasia may create giant gastric folds.

The intraepithelial lymphocytes cause the epithelium to appear vacuolated and acquire a clear cell appearance, particularly in the subnuclear region.

Other entities that mimic this pattern include:
 endocrine cell hyperplasia
 dystrophic gobletcells
 fixation artifact.

Immunohistochemical stains distinguish among these possibilities.

Pathology

As the name implies, lymphocytic gastritis is characterized by the presence of large numbers of mature lymphocytes infiltrating the surface and foveolar epithelium.

The increase in intraepithelial lymphocytes can be associated with marked chronic inflammatory cell infiltration of the lamina propria, activity, and focal erosions, or at the other extreme, only a minor increase in chronic inflammatory cells with no activity.

The histological picture is readily distinguished from ordinary H. pylori-associated chronic gastritis.

In the latter one finds four to seven lymphocytes per 100 epithelial cells, whereas 10 times this number can be found in lymphocytic gastritis.

Most cases have counts between 25 and 40 lymphocytes per 100 epithelial cells, the diagnostic threshold for lymphocytic gastritis being generally taken as being greater than 25 intraepithelial lymphocytes (IELs) per 100 cells.

The IELs are almost exclusively T-lymphocytes and the great majority (around 90%) are CD8+ suppressor cells.

The condition is frequently associated with the endoscopic entity "varioliform gastritis", which is characterized by nodular and eroded lesions running along the gastric rugae in the corpus while in some cases the endoscopic and histological appearances overlap with those of Menetrier disease.

An association between lymphocytic gastritis and celiac disease is becoming increasingly recognized

Etiology

 celiac disease (33%)
 Helicobacter pylori gastritis (19%)
 varioliform gastritis
 inflammatory polyp
 Crohn’s disease
 human immunodeficiency virus infection
 lymphoma
 esophageal carcinoma
 lymphocytic gastroenterocolitis

Differential diagnosis

Additionally, one must distinguish the lesions present in lymphocytic gastritis (particularly if lymphoepithelial lesions are present) and MALT lymphomas.

The lack of cytologic atypia in lymphocytic gastritis and the fact that the cells are T cells readily differentiates lymphocytic gastritis from the B-cell lesion of MALT lymphoma.

Feature	Lymphocytic Gastritis	MALT Lymphomas
Lymphocyte number	Significantly increased	Significantly increased
Lymphocyte distribution	Single cells or linear arrangement in the epithelium	Clusters of three or more lymphocytes in the epithelium
Lymphocyte type	Mature T cells	Malignant B cells
Perilymphocytic halo	Common	Uncommon
Significant epithelial destruction	No	Yes
Cytologic atypia of the lymphocytes	No	Yes
Diffuse lamina propria infiltration and destruction by atypical lymphocytes	No	Yes

References

 Wu TT, Hamilton SR. Lymphocytic gastritis: association with etiology and topology. Am J Surg Pathol. 1999 Feb;23(2):153-8. PMID: 9989841