Definition of Bone marrow aspiration

Bone marrow aspiration: The removal of a small amount of liquid bone marrow through a needle. The needle is placed through the top layer of bone, and a liquid sample containing bone marrow cells is obtained through the needle by sucking (aspirating) it into a syringe. The suction causes pain for a few moments. Bone marrow aspiration is done to diagnose and follow the progress of various conditions, including anemia and cancer, and to obtain marrow for transplantation.