Hepatic alveolar echinococcosis mimicking cholangiocarcinoma: a case study

Hepatic alveolar echinococcosis (HAE) is associated with significant disability and mortality. After infection, there is a prolonged asymptomatic latent period, and most patients present at a late stage when they seek medical treatment. The radiological features of HAE can resemble those of liver malignancies, posing diagnostic challenges. A 52-year-old male was admitted to our hospital with discomfort and pain in the upper right abdomen persisting for more than six months without an apparent trigger. Abdominal ultrasound revealed a heterogeneous mass in the right posterior lobe of the liver, characterised by an irregular shape and indistinct boundaries. Enhanced ultrasound demostrated slight hyper-enhancement of the peripheral area during the arterial phase and hypo-enhancement in the delayed phase, while the central area showed no enhancement. CT and MRI scans revealed a large abnormal lesion in the right posterior lobe and porta hepatis of the liver, accompanied by marked dilation of the intrahepatic bile ducts and multiple enlarged lymph nodes at the porta hepatis. The lesion’s edges exhibited mild enhancement in the delayed phase, whereas the centre showed no significant enhancement. Serum CA199 levels were markedly elevated, exceeding the upper reference limit by more than sevenfold. The patient’s serum rEm18-ELISA test for alveolar cyst was negative. The pathological diagnosis was obtained via ultrasound-guided liver biopsy. The initial biopsy showed no clear evidence of tumour lesions. A repeat biopsy revealed hepatic alveolar echinococcosis, with Candida infection in the necrotic tissue. Four months later, the patient underwent surgical treatment at another hospital. Pathological examination confirmed hepatic alveolar echinococcosis, and the patient made a good recovery. Hepatic alveolar echinococcosis can closely mimic perihilar cholangiocarcinoma, exhibiting almost identical imaging features. Initial biopsies may yield false-negative results due to sampling necrotic tissue. Therefore, it is essential to consider the patient’s epidemiological background, maintain a high index of suspicion, and perform repeat biopsies to ensure an accurate diagnosis. Furthermore, it is crucial to inhance heathcare professionals’ proficiency in both clinical and technical aspects, promote effective interdepartmental communication, and reduce the incidence of misdiagnosis.