Differential diagnosis of hepatocellular carcinoma 1. When the serum AFP is positive, HCC should be differentiated from the following diseases: (1) Chronic liver disease: such as hepatitis and cirrhosis, the patient’s serum AFP level should be dynamically observed. When liver disease is active, AFP is mostly active in the same direction as ALT, and is mostly transient or fluctuates repeatedly, usually not exceeding 400 μg/L for a short period of time. If the curves of AFP and ALT are separated, AFP rises and SGPT falls, i.e., AFP and ALT are heterogeneously active and/or AFP is persistently high, then the possibility of HCC should be alerted. (2) Tumors such as pregnancy, gonadal or embryonic type: Identification is mainly by medical history, physical examination, abdominopelvic ultrasound and CT examination. (3) Gastrointestinal tumors: Some adenocarcinomas of the gastrointestinal and pancreatic glands can also cause elevated serum AFP, called hepatoid adenocarcinoma. In addition to detailed medical history, physical examination and imaging, the determination of serum AFP heterogeneity can help to identify the origin of the tumor. For example, in gastric liver-like adenocarcinoma, AFP is dominated by lentil agglutinin unconjugated type. When serum AFP is negative, HCC should be differentiated from the following diseases: (1) secondary hepatocellular carcinoma: mostly seen in metastatic GI tumors, but also common in lung and breast cancer. Patients may have no background of liver disease, but their medical history may show GI tumor manifestations such as blood in stool, fullness and distension, anemia and weight loss, and normal serum AFP, while GI tumor markers such as CEA, CA199, CA50, CA724 and CA242 may be elevated. (2) The typical image of metastatic tumor can be seen as “bull’s-eye sign” (a halo around the mass and hypoechoic or hypointense in the center due to the lack of blood supply). or X-ray imaging may reveal primary cancerous lesions in the gastrointestinal tract. (2) Intrahepatic cholangiocarcinoma (ICC): it is a rare pathological type of primary hepatocellular carcinoma, with a predilection for age 30-50 years, non-specific clinical symptoms, no background of liver disease, mostly low AFP, and possibly elevated tumor markers such as CEA and CA199. However, the most meaningful CT scan shows that the blood supply to the liver is not as rich as that of HCC, and the fibrous component is more, and there is delayed enhancement with “fast-in, slow-out” characteristics. Sometimes irregular dilatation of intrahepatic bile ducts can be seen; there can also be localized atrophy of the liver lobe and invagination of the liver envelope. The diagnostic rate of imaging examination is not high, and it mainly depends on pathological examination after surgery. (3) Hepatic sarcoma: often without a background of liver disease, imaging shows a homogeneous solid occupancy with abundant blood supply, which is not easily distinguished from AFP-negative HCC. (4) benign liver lesions: including: ① hepatic adenoma: often without a background of liver disease, more women, often with a history of oral contraceptive use, and not easily distinguished from highly differentiated HCC. (iii) liver abscess: often with a history of dysentery or septic disease but no history of liver disease Ultrasound examination is often confused with hepatocellular carcinoma when the abscess is not liquefied or pus thick, and after liquefaction, it shows liquid dark area, which should be distinguished from central necrosis of hepatocellular carcinoma; DSA imaging does not have tumor vessels and staining. If necessary, fine needle aspiration can be performed at the pressure point. Anti-amoebic test treatment is a better differential diagnosis method. The clinical manifestations can be very similar to liver cancer; however, the disease generally has a long course, often with a history of many years, and progresses slowly, and the characteristic manifestation is tremor on percussion, i.e. “tremor of the encysted bursa”, often with a history of living in popular grazing areas and contact with dogs and sheep. Intradermal test (Casoni test) is a specific test with a positive rate of 90-95%. Ultrasound examination can reveal strong echogenicity of floating cysts in the cystic space, and CT sometimes reveals calcified head nodes in the cyst wall. Puncture biopsy is contraindicated because of the severe allergic reaction that can be induced.