Primary Colonic Eosinophilia and Eosinophilic Colitis in Adults

Abstract

The normal content of eosinophils in the adult colon and the criteria for the histopathologic diagnosis of eosinophilic colitis remain undefined. This study aimed at: (1) establishing the numbers of eosinophils in the normal adult colon; and (2) proposing a clinicopathologic framework for the diagnosis of primary colonic eosinophilia and eosinophilic colitis. To accomplish these goals, we counted the eosinophils in the right, transverse, and left colon of 159 adults with normal colonic histology. Using a database of 1.2 million patients with colonic biopsies, we extracted all adults with a diagnosis of colonic eosinophilia. We reviewed the slides from all cases and captured demographic, clinical, and pathologic data, including information about eosinophilia in other organs. We then compared the clinical manifestations of the study patients (those with no identifiable cause of eosinophilia) to those of patients with other types of colitis. The normal eosinophil counts (per mm) were 55.7±23.4 in the right, 41.0±18.6 in the transverse, and 28.6±17.2 in the left colon. Of the 194 study patients (eosinophil counts 166-5050/mm), 63 were asymptomatic and had a normal colonoscopy. Diarrhea and abdominal pain were the commonest indications for colonoscopy (38% and 27%, respectively) among the 131 patients who had symptoms, endoscopic abnormalities, or both. Neither clinical manifestations nor endoscopic appearance were sufficiently characteristic to elicit the suspicion of colonic eosinophilia. In conclusion, primary colonic eosinophilia was extremely rare in this series (<1 in 6000 patients); one third of these patients were asymptomatic. Their clinical manifestations were not distinctive and could not have led clinicians to suspect this condition; one third of the patients were asymptomatic. We suggest that regularly reporting high colonic eosinophilia may result in increased opportunities for clinicopathologic studies that might lead to a better definition of this still elusive entity.

Quantification of the duodenal eosinophil content in adults: a necessary step for an evidence‐based diagnosis of duodenal eosinophilia

“…Concurrent gastric eosinophilia (defined as >30/hpf) 9 was present in 14 patients (45.2%), and oesophageal eosinophilia (>15 eos/hpf) 1 gastritis in 11 patients (35.5%); and both in 6 patients. Of the seven patients who had a simultaneous colonoscopy with biopsies, four had colonic eosinophilia . Thus, of the 31 patients with elevated duodenal eosinophils, 21 had one or more other gastrointestinal organs involved by eosinophilia, likely indicating the presence of eosinophilic gastroenteritis.…”

“…The apparent lack of distinct manifestations associated with isolated increases in the eosinophilic content of the duodenal mucosa suggest that the distinction we made regarding eosinophilic colitis could also be usefully applied to the duodenum . In a study of 194 patients with isolated colonic eosinophilia, 63 (32.5%) were biopsied during a screening colonoscopy for the detestation of colon cancer and most of them had a normal endoscopy.…”

“…Initially we planned to count eosinophils within the surface epithelium, the crypt epithelium (“eosinophilic cryptitis”) and in the crypt space (“eosinophilic crypt abscess”) of the duodenum by applying the same method as we did in a previous study for the colon . However, intraepithelial eosinophils were detected in very few duodenal samples, and when present they were so rare that no analysable numbers could be generated.…”

The pathology and causes of tissue eosinophilia in the gastrointestinal tract

“…It is of note that 38% of patients with colonic eosinophilia in this series had no reported symptoms. Diarrhoea was present in 38% of patients overall, and, interestingly, was less common in those with the greatest number of eosinophils . Clearly, further clinical and pathological data are needed to better define the nature of this rare condition.…”

Eosinophilic Gastrointestinal Diseases in Childhood

“…EC is a rare inflammatory GI disorder characterized clinically by symptoms related to colonic dysfunction and colon biopsies histology indicating excessive accumulation of eosinophils [52]. The prevalence of EC is estimated to be about 2.1 per 100,000 individuals [30], with no prominent differences related to age or gender [19, 30], although some authors claimed a predominance of males [53].…”