Marked elevation of serum alpha-fetoprotein following Clonorchis sinensis infection: A rare case report

Clonorchiasis, also known as the liver fluke disease, is caused by eating raw freshwater fish or shrimps that contain Clonorchis sinensis cyst larvae, which mainly involves the hepatobiliary system. Chronic abdominal pain and distention, loss of appetite, and hepatomegaly are the most common clinical manifestation. Persistent infection with Clonorchis sinensis would result in chronic inflammation, epithelial hyperplasia, and periductal fibrosis and even progress to cholangiocarcinoma. Nevertheless, the majority of the infected people are asymptomatic or mildly symptomatic, contributing to its high misdiagnosis rate. Alpha-fetoprotein (AFP) is a well-known biomarker for hepatocellular carcinoma (HCC). A high level of AFP can also be caused by several benign diseases, causing confusion and influencing treatment decisions. So far, clonorchiasis with a markedly elevated level of AFP has been rarely reported. We present a case of clonorchiasis with a high level of AFP in a 52-year-old man. We hope to raise clinical awareness of this food-borne disease. Clonorchiasis should be considered in patients with extremely high levels of AFP, excluding HCC and germ cell tumors, especially if the patient has a history of ingesting raw freshwater fish or shrimps.