Clonorchiasis misdiagnosed as hepatic space-occupying lesion: a case report.

Clonorchis sinensis, a zoonotic parasitic infection, is contracted by consuming raw freshwater fish harboring infective larvae of the parasite. C. sinensis infection usually cause damage to the liver and biliary tract system. Chronic infection with C. sinensis can lead to long-term liver and bile duct damage, including hepatic fibrosis, and may increase the risk of developing cholangiocarcinoma (CCA). Nevertheless, a significant portion of infected individuals exhibit either asymptomatic or nonspecific, thereby contributing to a high rate of misdiagnosis. CA19-9 is a tumor-associated antigen that is found in normal glandular epithelium. Elevated levels of CA19-9 serve as an indicator for digestive tract and gynecological diseases and tumors. This case report reveals a 42-year-old female with clonorchiasis presented with elevated CA 19-9 levels, increased FDG uptake in the liver and celiac lymph node on FDG-PET imaging, leading to initial misdiagnosis as cholangiocarcinoma due to the overlap of symptoms with other benign conditions. Clonorchiasis often presents with vague symptoms and lacks sensitive diagnostic methods. During the acute phase, imaging findings may resemble inflammatory or malignant lesions, leading to misdiagnosis and missed diagnosis. To avoid unnecessary interventions, clinicians should consider the patient's overall condition and consult thoroughly to identify any atypical infections.