Sternal

sternal puncture insertion of a hollow needle into the manubrium of the sternum to obtain a sample of bone marrow. The sternum is chosen because of its accessibility and because it is a thin, flat bone. The procedure must be done under surgical asepsis. The clinician anesthetizes the skin and periosteum with a local anesthetic before introducing the sternal needle. The needle is designed with a special guard to prevent penetration beyond the desired depth. When cells are being aspirated into the syringe the patient may experience a sharp pain; otherwise the procedure should not be painful. Samples are examined for abnormal cells, for the proportion of cells in various stages of development, and for the characteristics of the blood cells that predominate. This information is used in conjunction with clinical findings and other tests in diagnosis of blood disorders such as leukemia, lymphoma, multiple myeloma, and anemia.