[Diseases in which too many blood cells are made in the bone marrow. ( NCI )] (UMLS (NCI) C0027022) =Neoplastic Process =Bone Marrow Disease; bone marrow cancer =Polycythaemia Vera; Anemia, Myelophthisic; Acute Erythroblastic Leukemia; Leukemoid reaction; Bone Marrow Fibrosis; Myeloid Metaplasia; Polycythaemia Vera; Thrombocytosis