Eosinophilic Ascites: A Rare Presentation of a Hematoma.

Idiopathic eosinophilic ascites (IEA) is a condition characterized by the eosinophilic infiltration of the peritoneal cavity without an identifiable underlying cause. We present the case of a 39-year-old female patient with no significant medical history who was referred for leukocytosis and abdominal discomfort. Imaging revealed a large, peripherally calcified intra-abdominal fluid collection, and subsequent paracentesis demonstrated eosinophilic ascites (EA). A thorough evaluation, including peripheral eosinophilia workup, malignancy screening (including imaging and cytology), infectious serologies (parasitic and fungal panels), autoimmune markers, and upper and lower endoscopy with biopsies, failed to identify a definitive etiology. Diagnostic laparoscopy confirmed a hematoma, and post-laparoscopy, the patient's symptoms and peripheral eosinophilia resolved. This case highlights the diagnostic challenges of EA, the importance of a systematic exclusionary approach, and the potential for an idiopathic, reactive eosinophilic process. Given the risk of recurrence or progression to an underlying disorder, long-term follow-up is warranted.