Cholangiocarcinoma is a malignant tumor originating from the intrahepatic or extrahepatic bile ducts. It is classified into intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC). Extrahepatic cholangiocarcinoma is further divided into hilar cholangiocarcinoma and distal cholangiocarcinoma.
Etiology
Risk factors for cholangiocarcinoma include primary sclerosing cholangitis, liver cirrhosis, liver fluke infection, obesity, Lynch syndrome, chronic viral hepatitis, cholelithiasis, biliary tract malformations, and inflammatory bowel disease.
Clinical Manifestations
Patients with intrahepatic cholangiocarcinoma often exhibit no specific symptoms in the early stages. As the disease progresses, symptoms such as abdominal discomfort, weight loss, hepatomegaly, or a palpable abdominal mass may appear, while biliary obstruction is relatively uncommon. Patients with hilar or extrahepatic cholangiocarcinoma frequently present with jaundice, which gradually worsens as the disease progresses. Other symptoms include pale gray or white stools, dark yellow urine, and pruritus, often accompanied by fatigue, weakness, and weight loss. Right upper quadrant pain, chills, and fever may indicate concurrent cholangitis.
Laboratory and Imaging Examinations
Laboratory Tests
CA19-9 and CEA have diagnostic and monitoring value for cholangiocarcinoma, but their sensitivity and specificity are relatively low.
Imaging Examinations
Ultrasound is the initial imaging modality of choice and helps distinguish between masses and stones, identify the site of obstruction, and assess portal vein involvement. CT imaging can demonstrate the extent of tissue involvement around the intrahepatic and extrahepatic bile ducts, providing information for staging and surgical feasibility. MRI can clearly delineate the tumor's extent and detect intrahepatic metastases. MRCP provides a detailed evaluation of bile duct branches and the extent of bile duct involvement. Duodenoscopy allows direct visualization of the ampulla in cases of distal cholangiocarcinoma. Emerging techniques such as peroral cholangioscopy enable direct visualization of intraductal lesions and allow biopsy sampling.
Pathology
Pathological specimens are primarily obtained from bile cytology through drainage, bile duct brush cytology under ERCP guidance, cholangioscopic biopsy, fine-needle aspiration, or percutaneous biopsy under ultrasound or CT guidance. Techniques such as liquid-based cytology, special staining, immunohistochemistry, and molecular pathology can help confirm the nature of the lesion.
Diagnosis
A clinical diagnosis can be made based on the typical imaging features of cholangiocarcinoma, while a definitive diagnosis requires pathological confirmation.
Treatment
Surgical resection is the preferred treatment for cholangiocarcinoma. Surgery aims to achieve negative resection margins while performing lymph node dissection. For unresectable tumors, neoadjuvant chemotherapy may help downstage the tumor, increasing the likelihood of radical surgical resection. For patients with unresectable tumors and biliary obstruction, bile duct stent placement can provide drainage, alleviate symptoms, and improve survival. Complex hilar tumors may require nasobiliary drainage under ERCP or percutaneous biliary drainage. After relieving biliary obstruction, systemic or local treatments such as chemotherapy, molecular targeted therapy, immunotherapy, or combination therapies can be administered. Endoscopic-guided intraluminal radiofrequency ablation and photodynamic therapy may help control local tumor progression and prolong survival.