Clonorchis sinensis: a mimic of hepatic mucinous cystic neoplasm or just a fluke?

Liver flukes, endemic in East Asia, are parasites that can infect humans and cause liver and bile duct disease. While most infected individuals are asymptomatic, chronic infection can lead to structural hepatobiliary manifestations including hepatomegaly, intrahepatic bile duct dilatation, epithelial hyperplasia, periductal fibrosis, and potentially cholangiocarcinoma. There are no reports of human cases of liver fluke infection presenting as a hepatic cystic lesion. We present the case of a 52-year-old asymptomatic Chinese immigrant presenting with a suspected mucinous cystic neoplasm of the liver. CT and Ultrasound examinations demonstrated an enlarging complex cyst involving segments II and III. Liver function tests, hydatid serology and tumour markers were normal. He underwent elective laparoscopic left hemi-hepatectomy with liver fluke discovered on histology. Subsequent genetic testing confirmed Clonorchis sinensis infection. The patient made an uneventful recovery from surgery and was treated with anthelminthic therapy. This case highlights the importance of considering liver fluke as a differential diagnosis for hepatic cystic lesions in patients from endemic regions. Appropriate diagnosis could avoid surgery, whilst targeted anthelminthic therapy minimises the risk of chronic infection and associated complications, including cholangiocarcinoma.