Recurrent Eosinophilic Pancreatitis With Eosinophilic Gastroenteritis: A Case Report.

BACKGROUND Eosinophilic pancreatitis (EP), representing <1% of pancreatitis cases, poses significant diagnostic challenges due to its heterogeneous manifestations ranging from mild to life-threatening. The overlapping clinical symptoms and imaging features with other types of pancreatitis often make EP particularly difficult to differentiate. Although tissue demonstration of eosinophilic infiltration (>10/high-power field) after excluding secondary causes is diagnostic, the invasiveness of pancreatic biopsy and disease rarity lead to high misdiagnosis rates in clinical practice. The present case report includes detailed imaging (CT, MRCP, EUS) and histopathology findings, providing a visual guide for clinicians encountering similar cases. CASE REPORT We present the case of a 68-year-old Chinese man diagnosed with EP manifesting as recurrent pancreatitis episodes. His chief concern was recurrent severe abdominal pain of unknown etiology. During his first admission, an upper endoscopy was performed despite the absence of gastrointestinal symptoms and revealed eosinophilic gastroenteritis (EGE). One year later, upon recurrence of pancreatitis, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the pancreas was performed, confirming EP with approximately 15 eosinophils/high-power field. The patient's symptoms and pancreatic duct dilation resolved rapidly following corticosteroid therapy. The diagnosis was definitively established based on a composite framework comprising recurrent pancreatitis, persistent peripheral eosinophilia, the rigorous exclusion of secondary causes, and histological confirmation of eosinophilic infiltration via EUS-FNA. CONCLUSIONS Eosinophilic pancreatitis (EP) is a rare yet potentially severe acute pancreatitis subtype requiring early diagnosis. It can also be associated with subclinical eosinophilic gastroenteritis (EGE). Immunomodulatory therapy, especially glucocorticoids, is highly effective. Our findings support using endoscopy in cases of unexplained pancreatitis for a definitive histological diagnosis. Prompt diagnosis is crucial for initiating effective corticosteroid therapy, which can resolve symptoms and prevent disease progression.