Natural History Study of Children and Adults With Fibrolamellar Hepatocellular Carcinoma

Background: Fibrolamellar Hepatocellular Carcinoma (FL-HCC) is a rare liver cancer. It usually occurs in young people who have no history of liver disease. Currently the only effective treatment option is surgery that removes the tumor and part of the liver. Researchers want to study the course of the disease to learn more about it. Objective: To collect samples from people with FL-HCC to learn more about the disease and help develop new treatments. Eligibility: People any age with FL-HCC Design: Participants must be enrolled on another NIH protocol. Participants will have at least 1 study visit. They will have: * A medical and cancer history * A physical exam * A review of their symptoms and their ability to do normal activities * Tests to produce images of the body. They may have a scan (CT) that uses a small amount of radiation. Or they may have a scan (MRI) that uses a magnetic field. These will examine the chest, abdomen, and pelvis. * Blood tests Researchers will study previous tumor samples if they are available. If participants come to NIH for visits on other studies, data will be collected about their disease, tests, treatments, and responses. Tumor tissue will be collected if participants are having it taken for a procedure. All other participants will be contacted to collect this data. They will be contacted once a month for 1 year and 2 times a year after that. Participants will be asked to contact researchers when their health changes. They may come in for more tests.