Pseudotumor of the stomach caused by hypereosinophilic syndromes: A case report and literature review

Abstract

Abstract Background Hypereosinophilic syndromes (HES) constitute a rare group of disorders marked by abnormal eosinophil accumulation in the blood or peripheral tissues. The clinical manifestations of HES can vary greatly, ranging from asymptomatic to life-threatening. Occasionally, HES can mimic organ-specific tumors or malignancies, posing diagnostic challenges and potential overtreatment. Case Presentation We presented a 51-year-old female enduring epigastric pain, fatigue, and weight loss for 8 months. Endoscopy revealed a protuberant lesion with mucosal hyperemia in the stomach. Radiological assessments exhibited gastric wall thickness, lymphadenectasis, and irregular pulmonary nodules (5-15 mm). PET/CT demonstrated thickened gastric walls, multiple enlarged lymph nodes with heightened FDG uptake, resembling metastatic gastric carcinoma. The endoscopic ultrasound (EUS)-guided biopsy of perigastric lymph nodes revealed eosinophil infiltration. Absolute eosinophil count (AEC) was 580/μL, and total serum IgE level was 1850 IU/ml. Bone marrow biopsy showed no abnormalities. A tentative diagnosis of HES involving multiple organs, prominently the stomach, was established. Treatment initiated with a 3-day intravenous methylprednisolone course (80 mg/day), transitioning to oral prednisone. The dose was gradually reduced from 50 mg/day to a maintenance level of 15 mg/day over four months, complemented by monthly cyclophosphamide pulse treatments. The patient achieved complete clinical and biochemical remission without recurrence during the 1-year follow-up. Conclusions Occasional mimicking of tumors in medical imaging by HES emphasizes the importance of biopsies, comprehensive organ evaluation, and excluding other potential causes. Systemic oral steroid use can serve as a diagnostic approach. Timely identification of HES-related pseudotumors and appropriate steroid treatment lead to a positive outcome without unnecessary intervention.