cholangiocarcinoma development. Genetic conditions: untreated hereditary hemochromatosis, alpha-1-antitrypsin deficiency, glycogen storage diseases, porphyria cutanea tarda, Wilson's disease, tyrosinemia have all been associated with development of HCC. Oral contraceptive pill: There is insufficient evidence to label oral contraceptives as a risk factor. However, recent studies have found that taking oral contraceptives for longer than 5 years is associated with HCC. Children Childhood liver cancer is uncommon. The liver cancer sub-types most commonly seen in children are hepatoblastoma, hepatocellular carcinoma, embryomal sarcoma of liver, infantile choriocarcinoma of liver, and biliary rhabdomyosarcoma. Increased risk for liver cancer in children can be caused by Beckwith–Wiedemann syndrome (associated with hepatoblastoma), familial adenomatous polyposis (associated with hepatoblastoma), low birth weight (associated with hepatoblastoma), Progressive familial intrahepatic cholestasis (associated with HCC) and Trisomy 18 (associated with hepatoblastoma). Diagnosis Many imaging modalities are used to aid in the diagnosis of liver cancer. For HCC these include medical ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). When imaging the liver with ultrasound, large lesions are likely to be HCC (e.g., a mass greater than 2 cm has more than 95% chance of being HCC).Given the blood flow to the liver, HCC would be most visible when the contrast flows through the arteries of the liver (also called the arterial phase) rather than when the contrast flows through the veins (also called the venous phase). Sometimes doctors will get a liver biopsy, if they are worried about HCC and the imaging studies (CT or MRI) do not have clear results. The majority of cholangiocarcimas occur in the hilar region of the liver, and often present as bile duct obstruction. If the cause of obstruction is suspected to be malignant, endoscopic retrograde cholangiopancreatography (ERCP), ultrasound, CT, MRI and magnetic resonance cholangiopancreatography (MRCP) are used. Tumor markers, chemicals sometimes found in the blood of people with cancer, can be helpful in diagnosing and monitoring the course of liver cancers. High levels of alpha-fetoprotein (AFP) in the blood can be found in many cases of HCC and intrahepatic cholangiocarcinoma. Of note, AFP is most useful for monitoring if liver cancers come back after treatment rather than for initial diagnosis. Cholangiocarcinoma can be detected with these commonly used tumor markers: carbohydrate antigen 19-9 (CA 19–9), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125). These tumor markers are found in primary liver cancers, as well as in other cancers and certain other disorders. Prevention