PRIMARY GALLBLADDER CARCINOMA

Primary gallbladder carcinoma
Cancer of the gallbladder is usually associated with gallstones and a history of cholecystitis. Most often, the gallbladder lumen is occupied by a solid mass which may have the appearance of a large polyp. The wall appears thickened and irregular and shadowing from the stones may obscure it posteriorly. A bile-filled lumen may be absent, further complicating the ultrasound diagnosis.

In a porcelain gallbladder (calcification of the gallbladder wall), which is associated with gallbladder carcinoma, the shadowing usually obscures any lesion in the lumen, making the detection of any lesion present almost impossible.

Particular risk factors for gallbladder carcinoma include large stones, polyps of over 1 cm in size, porcelain gallbladder and, occasionally, choledochal cyst due to anomalous junction of the pancreatobiliary ducts.

The carcinoma itself is frequently asymptomatic in the early stages, and patients tend to present with symptoms relating to the stones. It is a highly malignant lesion which quickly metastasizes to the liver and portal nodes and has a very poor prognosis, with a curative surgical resection rate of around 15–20%.

Doppler may assist in differentiating carcinoma from other causes of gallbladder wall thickening, but further staging with CT is usually necessary. Ultrasound may also demonstrate local spread into the adjacent liver.