In brief: Abnormal wrist bone. The lunate is one of eight bones in the wrist. It is shaped like a half-moon and therefore called the lunate. Breakdown of this bone is known as kienbock's disease. The exact cause of this condition is not known. It may be related to various anatomical features unique to you. It may be genetically related.
Quick Answer. Atypical cells, the presence of which is sometimes called dysplasia, have a number of causes that range from infection and/or inflammation to normal aging. Atypical cells usually revert back into normal cells once the cause is identified and treated.
Rare causes of anemia due to a hypoplastic bone marrow include familial disorders and the acquired pure red cell aplasias. The latter are characterized by a virtual absence of erythroid precursors in the bone marrow, with normal numbers of granulocytic precursors and megakaryocytes.