True about Biliary cystic adenocarcinoma: (A) CT scan is used for diagnosis, (B) CA 19-9 is elevated, (C) intrahepatic location, (D) Extrahepatic location
Answer is A. Hepatic cystadenocarcinoma arising from pre-existing cystadenoma with mesenchymal stroma, which occurs only in young females, carries good prognosis resection is the treatment it carries a good prognosis. MRI is diagnostic. 
US/CT scan is also helpful. ERCP is done to identify communication with the biliary system usually to proximal left hepatic duct.