Most common gallbladder carcinoma is?

ANSWER: (D) AdenocarcinomaREF: Schwartz 9th ed chapter 32 Between 80 and 90% of the gallbladder tumors are adenocarcinomas. Squamous cell, adenosquamous, oat cell, and other anaplastic lesions occur rarely. The histologic subtypes of gallbladder adenocarcinomas include papillary, nodular, and tubular. Less than 10% are of the papillary type, but these are associated with an overall better outcome, as they are most commonly diagnosed while localized to the gallbladder. Cancer of the gallbladder spreads through the lymphatics, with venous drainage, and with direct invasion into the liver parenchyma. Lymphatic flow from the gallbladder drains first to the cystic duct node (Calot's), then the pericholedochal and hilar nodes, and finally the peripancreatic, duodenal, periportal, celiac, and superior mesenteric artery nodes. The gallbladder veins drain directly into the adjacent liver, usually segments IV and V, where tumor invasion is common