From Eosinophilic Gastroenteritis to Chronic Eosinophilic Leukemia: A Case of Hypereosinophilia

Abstract

Introduction Hypereosinophilia is generally defined as a peripheral blood eosinophil count greater than 1500/mm3 and can be associated with reactive (secondary) or hematologic (primary) disorders, which can lead to end-organ damage. We present a patient with gastrointestinal symptoms in the setting of absolute eosinophilia. Work-up was initially suggestive of eosinophilic gastroenteritis, a rare inflammatory disorder characterized by eosinophilic tissue infiltration with no known natural progression to date. However, additional studies revealed a clonal genetic abnormality on chromosomal analysis in the diagnosis of chronic eosinophilic leukemia, not otherwise specified (CEL, NOS). Case Description An 82-year-old female with history of psoriatic arthritis presented with a 2-week history of watery, nonbloody bowel movements (5-20 per day) along with abdominal cramping, nausea and worsening oral intolerance. Vital signs and physical exam were unremarkable. Laboratory studies were significant for a WBC of 25,000 (40% eosinophils) and elevated IgE level at 138IU/mL. CT of the abdomen was also unremarkable.2578_A Figure 1. Duodenal biopsy, increased eosinophils infiltrating epithelium and lamina propria.2578_B Figure 2. Bone marrow biopsy, hypercellular bone marrow with eosinophilia.An esophagogastroduodenoscopy was performed, demonstrating diffuse duodenal erythema, edema and villous blunting as well as erythematous and hypertrophied gastric folds. Random duodenal, gastric, esophageal, and colonic biopsies revealed increased eosinophils (60 to >100 eos/hpf). Bone marrow biopsy was notable for hypercellularity and marked eosinophilia. The chromosomal analysis detected a clonal cytogenetic abnormality, del(11q), satisfying the 2017 WHO diagnostic criteria for CEL, NOS. The patient was treated with corticosteroids with resolution of absolute eosinophilia and gastrointestinal symptoms. Discussion This case elucidates the importance of undergoing a complete evaluation for hypereosinophilia, beginning with assessing for secondary causes, followed by thorough hematologic diagnostic studies. The localization of the patient's symptoms in the gastrointestinal tract, coupled with biopsy-proven eosinophilic infiltration, pointed initially towards eosinophilic gastroenteritis. However, the abnormal chromosomal analysis proved the diagnosis of CEL, NOS. As more cases suggestive of eosinophilic gastroenteritis emerge, the hope is to better understand the pathogenesis and natural progression of this rare disease, as well as to compare the effectiveness of therapeutic strategies with that of the hematologydriven processes.