<prompt> True about Biliary cystic adenocarcinomaCT scan is used for diagnosisCA 19-9 is elevatedintrahepatic locationExtrahepatic location  <response>: 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. USCT scan is also helpful. ERCP is done to identify communication with the biliary system usually to proximal left hepatic duct. 