In adult patients, an ideal bone marrow specimen consists of both a bone marrow aspirate (the removal of only the fluid portion, known as the marrow) and a biopsy (sample of the more solid portion, which is the bone with marrow inside). The left or right posterior iliac crest is the most commonly used site to obtain a bone marrow biopsy and aspiration (see image). The iliac crest is preferred for safety reasons, because no major blood vessels or organs are located close to this area. Typically, sampling from the iliac crest also results in less pain to the patient and is conveniently located for the practoitioner performing the procedure. Alternate sites include the left or right anterior (front) iliac crest, the sternum (involves higher risk due to location near the heart and major blood vessels), and tibia (typically used only in infants less than eighteen months old).
The bone marrow specimen may be collected by a pathologist, an oncologist, or other provider, depending on local practice.
Patient preference regarding the use of sedation may determine where the procedure is performed. Often, bone marrow specimens can be obtained in a clinic setting using only local anesthetic, such as lidocaine. Bone marrow specimen collection can also be performed under conscious sedation in an outpatient setting or on the inpatient hospital unit. Clinicians may prefer to perform the collection in the operating room (OR) under general anesthesia. This is useful for patients that may experience complications, who express extreme anxiousness of the procedure, or when the collection is performed in combination with another procedure, such as a lymph node biopsy or placement of a port.
Depending on practitioner preference, the sequence of bone marrow aspiration and bone biopsy sampling may vary. A needle is used to obtain the samples. It is common to collect the bone marrow biopsy first so as to avoid aspiration artifact and because the aspiration tends to be the most painful part of the procedure. However, some practitioners may prefer collecting the bone marrow aspirate first to prevent contamination of the aspirate with peripheral blood, which could happen when the bone biopsy is taken. Separate needles and sampling locations on the posterior iliac crest can also be used for each procedure to obtain optimal aspirates and biopsies.
