Evaluation, Treatment, and Natural History of Children and Young Adults With Cancer or Rare Diseases

Background: Children and adults are referred to the Pediatric Oncology Branch (POB) for possible enrollment in clinical protocols for the treatment of cancer or other rare diseases. While some children are not eligible for a specific protocol, they may present with disease manifestations that offer the potential for important new insights into the pathogenesis or clinical behavior of their underlying disease. In addition, children who have completed participation in a clinical protocol but do not currently have therapeutic protocol alternatives may continue to provide POB with important information. Diseases of interest to the POB include, but are not limited to lymphoma, brain tumors, Ewing's sarcoma, leukemia, neuroectodermal tumors, osteosarcoma, rhabdomyosarcoma, RAS-related syndromes and inherited immune disorders, amongst others. Hence, serial clinical evaluation of such patients, including the performance of clinical, laboratory, and diagnostic studies to help elucidate longitudinally the underlying disease mechanisms, and when clinically indicated standard care therapies, will assist POB meet its overall mission. Objectives: To be able to follow and evaluate children and adults with cancer or pre-cancer syndromes and other rare diseases referred to the Pediatric Oncology Branch who present with disease manifestations that lend themselves to clinical evaluation and are of unique scientific importance. Eligibility: Patients who are evaluated by the Pediatric Oncology Branch and are: * Children and adults with cancer (or a pre-cancer syndrome or rare disease), with disease manifestations of special interest to Pediatric Oncology Branch investigators. * Patients must be greater than or equal to 2 years and less than or equal to 40 years of age at the time of study enrollment. Design: The medical procedures or tests will be selected for each patient on the basis of his/her individual diagnosis (or presumed diagnosis). When clinically indicated, standard therapy will be administered and patients will be followed according to standard medical practice. Specimens may be collected for clinical care purposes only to evaluate the patient s status. No investigational tests, drugs or therapies will be administered in this protocol.