This protocol is designed to allow the evaluation, follow up, and standard medical care of patients (and when appropriate, their stem cell donor) with bone marrow failure states, cytopenias, metastatic solid tumors, or hematologic malignancies not currently entered on an active NHLBI Hematology Branch protocol or not being screened for an active NHLBI research protocol. Its purpose is to allow investigation into the hematologic problems of these patients for the primary purpose of teaching and furthering general hematologic knowledge. The ability to evaluate and treat patients with a wide variety of hematologic disease is critical to maintaining our accreditation as a hematology fellowship program and training our fellows to be competent hematologists, as well as for keeping all staff, including senior staff, up-to-date and familiar with the evaluation and treatment of patients with a wide spectrum of hematologic disease. It also allows the Hematology Branch to evaluate patients referred with rare or as yet undiagnosed hematologic problems, both potentially benefiting the patient and stimulating new research directions for the Hematology Branch in the future. Periodic follow-up and treatment of patients previously entered on Hematology Branch protocols in order to monitor the long-term course of the underlying hematologic state and the consequences of experimental treatments is also required for fellowship training, and for maintenance of good referral relationships with patients and their physicians.