Cancer-like eosinophilic gastritis

Histopathologic diagnosis of eosinophilic conditions in the gastrointestinal tract

Eosinophils, a constitutive component of the columnar-lined gastrointestinal tract, play an essential role in allergic responses and parasitic infections. The tissue density of these cells also increases in a variety of conditions of uncertain etiology. With the exception of the esophageal squamous epithelium, in which no eosinophils are normally present, the population of normal eosinophils in the remainder of the luminal gut is poorly defined. Therefore, histopathologists must rely on their subjective judgment to determine when a diagnosis of eosinophilic gastritis, enteritis, or colitis should be rendered. Eosinophilic esophagitis is currently the best defined and most studied eosinophilic condition of the digestive tract; therefore, the confidence in accurate diagnosis is increasing. In contrast, the characteristic clinicopathologic features of eosinophilic conditions affecting other parts of the digestive tract remain somewhat elusive. This review was designed to present pathologists with simple and practical information for the biopsy-based histopathologic diagnosis of eosinophilic esophagitis, gastritis, enteritis, and colitis. It was prepared by critically reviewing more than 200 articles on the topic, along with incorporating evidence accumulated through our own collective experience. We anticipate that by increasing pathologists' confidence in reporting these abnormal but often nameless eosinophilic infiltrates, we can help better define and characterize their significance.

Eosinophilic gastritis: histopathological characterization and quantification of the normal gastric eosinophil content

There is limited information about normal eosinophil counts in the gastric mucosa. The purpose of this study was to evaluate the histopathology of 60 patients whose biopsies showed increased eosinophils in the gastric mucosa. We also investigated the eosinophil content in gastric biopsies from normal controls (matched for age, sex, and zip code), from patients with Helicobacter pylori gastritis, and patients with Crohn's disease. Eosinophils were counted in five random high-power fields (HPFs) and reported in eosinophils/mm(2). Involvement of the muscularis mucosae or submucosa, sheets of eosinophils, and infiltration of the gastric epithelium were also evaluated. The median eosinophil count in the study patients was 539 eosinophils/mm(2); mean±SD=653±418 eosinophils/mm(2); range 127-2108. Sheets of eosinophils were seen in 38 patients, 27 showed involvement of the muscularis mucosae or submucosa. There were 7 patients without epithelial infiltration by eosinophils, whereas 34 were tallied as rare and 19 were scored as abundant. No study patient had no evidence of H. pylori. The mean eosinophil count for the 135 normal controls was 15.5±16.8 SD eosinophils/mm(2) (range 0-110); in the 93 controls with H. pylori gastritis the mean eosinophil count was 25±32.6 SD eosinophils/mm(2) (range 0-219); and for the 53 controls with Crohn's disease it was 31.4±44.4 SD eosinophils/mm(2) (range 0-203). There were no significant differences between the counts in biopsies from the antrum and corpus, and no significant variations by age, geographic location, or season. This study confirms that, in the United States population, the normal gastric eosinophilic counts are usually <38 eosinophils/mm(2). We recommend 'histological eosinophilic gastritis' for the diagnosis of gastric biopsies that show an average density ≥127 eosinophils/mm(2) (or ≥30 eosinophils per HPF) in at least five HPFs in the absence of known associated causes of eosinophilia.

Eosinophilia in a patient with cyclical vomiting: a case report

Background

Eosinophilic gastritis is related to eosinophilic gastroenteritis, varying only in regards to the extent of disease and small bowel involvement. Common symptoms reported are similar to our patient's including: abdominal pain, epigastric pain, anorexia, bloating, weight loss, diarrhea, ankle edema, dysphagia, melaena and postprandial nausea and vomiting. Microscopic features of eosinophilic infiltration usually occur in the lamina propria or submucosa with perivascular aggregates. The disease is likely mediated by eosinophils activated by various cytokines and chemokines. Therapy centers around the use of immunosuppressive agents and dietary therapy if food allergy is a factor.

Case presentation

The patient is a 31 year old Caucasian female with a past medical history significant for ulcerative colitis. She presented with recurrent bouts of vomiting, abdominal pain and chest discomfort of 11 months duration. The bouts of vomiting had been reoccurring every 7–10 days, with each episode lasting for 1–3 days. This was associated with extreme weakness and cachexia. Gastric biopsies revealed intense eosinophilic infiltration. The patient responded to glucocorticoids and azathioprine. The differential diagnosis and molecular pathogenesis of eosinophilic gastritis as well as the molecular effects of glucocorticoids in eosinophilic disorders are discussed.

Conclusions

The patient responded to a combination of glucocorticosteroids and azathioprine with decreased eosinophilia and symptoms. It is likely that eosinophil-active cytokines such as interleukin-3 (IL-3), granulocyte macrophage colony stimulating factor (GM-CSF) and IL-5 play pivotal roles in this disease. Chemokines such as eotaxin may be involved in eosinophil recruitment. These mediators are downregulated or inhibited by the use of immunosuppressive medications.