First case report of retroperitoneal metastasis of fascioliasis after surgery

RATIONALE Fascioliasis is a rare cause of liver abscesses, and its clinical course consists of hepatic phase and biliary phase. PATIENT CONCERNS We describe a 58-year-old female patient who presented with a 2-month history of intermittent fever and abdominal pain. An abdominal computed tomography (CT) revealed confluent low-density lesions in the liver. Complete surgical resection of these abscesses was performed, and postoperative pathological examination and serological tests confirmed a diagnosis of fascioliasis. However, 4 months after the surgery, follow-up CT revealed a lesion in the retroperitoneal area. Meanwhile, ultrasonography-guided percutaneous needle biopsy of the retroperitoneal lesion was performed, and a parasitic infection was suspected. DIAGNOSES Retroperitoneal metastasis of hepatic phase fascioliasis. INTERVENTIONS The patient received parasitic resistance treatment with triclabendazole at a dose of 10 mg/kg/d for 2 consecutive days. OUTCOMES After 2 courses of triclabendazole therapy, the retroperitoneal metastasis regressed to a minor lesion. LESSONS To the best of our knowledge, this is the first case report of retroperitoneal metastasis of fascioliasis, aimed at helping recognize the clinical features and treatment options of this rare disease.