Clinical, Laboratory and Epidemiologic Characterization of Individuals and Families at High Risk of Hematologic Cancer

Background: * Individuals may be prone to develop blood or lymph node cancers (leukemia or lymphoma) for a variety of reasons, including genetic predisposition to these cancers, environmental exposures or other medical conditions. * Studies of people and families at high risk of cancer often lead to clues about their cause that may also be important regarding the sporadic occurrence of these cancers in the general population. * Identifying genetic or environmental factors that play a role in the development of these diseases may be important in developing prevention trials, screening programs and treatments. Objectives: * Describe the cancers and other conditions in families with blood or lymph node cancer. * Find and describe genes that may cause blood and lymph node cancer, and understand how they work in families. * Use laboratory methods to try to determine if it is possible to identify who is at highest risk of blood or lymph node cancer. * Test how genes act with other factors to alter the risk of disease, its severity or its manifestations in families. Eligibility: * Individuals of any age with a personal or family history of a blood or lymph node cancer. * Individuals with a personal or family history of medical conditions or environmental exposures that may predispose to blood or lymph node cancer. Design: * Participants complete questionnaires about their personal and family medical history and provide consent for researchers to review their medical records and pathology materials related to their care and those of deceased relatives with blood or lymph node cancer, tumors, or other related illnesses for whom they are the legally authorized representative. * Participants donate a sample of blood or cheek cells, or a lock of hair for genetic studies. * Patients may also be evaluated at the NIH Clinical Center by one or more of the following specialists: cancer doctor or blood specialist, medical geneticist, research nurses or clinical social worker. They may have blood and urine tests and a cheek swab or mouth wash to collect cheek cells. Some patients may also be asked to have x-rays and routine imaging, such as CT scans or ultrasound tests, cell surface markers, skin biopsy, and, with special consents, bone marrow biopsy, MRI or PET scans, apheresis or fluorescein angiography and photography.