Gallbladder cancer is the most common malignant tumor of the biliary system. The cause is unknown, but it may be related to the long-term irritation of gallbladder stones and chronic cholecystitis. Early asymptomatic, it is difficult to obtain the diagnosis. Patients presenting with symptoms are mostly in the progressive stage, which is easier to diagnose by imaging, but the prognosis is poor. Risk factors of gallbladder cancer emale is more common, and the ratio of male to female is 1:3; the age of onset is mostly over forth years; fat. Pathologic classification of gallbladder cancer The majority of gallbladder cancer is adenocarcinoma, while other less common pathological subtypes include papillary adenocarcinoma, mucinous carcinoma, squamous carcinoma, and adenosquamous carcinoma. The majority of gallbladder cancers are adenocarcinomas. The cause is unknown. Gallbladder stones and chronic cholecystitis may be the causative factors. Pathologically, it can be divided into four types: 1) sclerosing carcinoma, 2) colloid carcinoma, 3) squamous epithelial carcinoma, and 4) papillary carcinoma. Sonographic features Gallbladder carcinoma can be divided into five types: nodular, myxomatous, thick walled, mixed and solid. 1. Small nodular type, the lesion is usually 1~2.5cm, with narrow base, regular polyp-like or uneven surface, wide base, papillary and other echogenic masses bulging towards the cavity; combined with multiple stones, it is easy to miss the diagnosis, and the position should be changed to make the stones move in order to observe the change of the wall of the neck of the capsule. 2.Muscarinic umbrella type is a myxoid mass with a wide base and irregular edges protruding into the gallbladder cavity, which is weakly echogenic or isoechoic. The base of the tumor is not wide and the edge is not neat when it is single, and it can be connected into pieces when it is multiple. The bile mud around the tumor may be point-like echo. 3. Wall-thickness type: limited thickening of the wall of a certain part of the gallbladder, especially the uneven thickening and elevation of the inner wall layer, which is isoechoic, which is the infiltration of the cancer into the wall of the gallbladder. Mixed type: papillary, tunica albuginea and wall thickening are mixed. Solid mass type: the gallbladder is enlarged, and the normal liquid gallbladder cavity disappears, showing a solid mass with weak echogenicity or coarse and uneven echogenicity; or the gallbladder cavity is filled with heterogeneous plaque-like echogenicity, sometimes accompanied by stones and acoustic shadows; this type tends to infiltrate the hepatic parenchyma and is not clearly demarcated from the liver. 6.Doppler ultrasound CDFI, CDE can show the tumor base and internal pulsatile blood flow signals, the spectrum of high resistance arterial blood, three-dimensional more clearly show the distribution of blood vessels. Diagnostic ideas and differential diagnosis 1, ask the medical history, whether the patient’s condition is progressive aggravation 2, ultrasound see the tumor visible in the gallbladder 3, need to be differentiated from the gallbladder wall itself benign lesions formed by thickening or bulging polypoid lesions. Chronic inflammation is uniform thickening, the inner wall is regular, no infiltration; adenomyosis of the gallbladder is characterized by small cystic structures within the thickened wall. Gallbladder polyps are generally less than 1cm, and there is no change in the follow-up observation. 4, bile mud, pus mass, blood clot, sound shadow is not obvious sediment-like stones are easily confused with gallbladder cancer. Change of body position can distinguish them. 5. The incidence of gallbladder stones combined with gallbladder cancer is high, and more stones with high echogenic mass and acoustic shadow masking the tumor are the main reasons for missed diagnosis.