Sarcomatoid carcinoma of the gall bladder.

Primary gallbladder carcinoma is a malignant neoplasm with an incidence of 1.2 cases per 100 000 people each year. Its occurrence increases with age, particularly in women. It is the fifth most common cancer of the gastrointestinal tract, and the most common malignancy in the biliary tract. Adenocarcinoma is the most common type of gallbladder neoplasm whereas sarcomatoid carcinoma is rare with an incidence of less than one percent of all malignant gall bladder neoplasms. Sarcomatoid carcinomas are composed of malignant epithelial and sarcomatous components, sometimes with heterologous sarcomatous elements. In general, conservative treatments are thought to be unfavourable to the tumor. Prognosis is poor following curative resection for carcinosarcoma of the gall bladder because of recurrence as systemic metastasis of the liver and peritoneal dissemination.