SAMPLING: BONE MARROW

Bone marrow is a tissue in the central cavity of bones. Is a hematopoietic tissue, that is to say, it continually makes cells called "stem cells" originally three blood cell lines

→ Directions
• The levy is necessary for the diagnosis of leukemia: it will highlight the proliferation of white blood cells mature or immature for the type of leukemia (lymphoid or myeloid).
• It is part of the staging of lymphoma, in search of an impaired bone marrow.
• It may be mentioned in the context of disease surveillance during and after treatment.
• It is conducted at a bone marrow transplant, the patient himself (autologous) or from a donor (allograft).

→ Sampling methods
We can take the bone marrow in two ways, by sternal puncture or biopsy (also called bone biopsy).
• The sternal puncture
After local anesthesia of the skin, sternal puncture is made on the curved part of the sternum with a needle called a trocar. Bone marrow, which has the consistency of a thin blood is sucked by a syringe and the sample is then spread on slides and examined microscopically for cytological examination or myelogram.
• Bone marrow biopsy
It complements the sternal puncture if the information provided by it are insufficient (eg if the marrow contains few cells or if it is very fibrous).
It is performed under local anesthesia on a pelvis bone, above the buttock. The bone harvest is performed using a trocar. After preparation and staining, bone tissue is examined microscopically for histological examination.

→ Disadvantages
These samples are generally well tolerated and relatively painless. A small local sensitivity is possible, yielding easily to analgesic medicines.

There are no cons-indications for these examinations. However, it should tell a doctor about taking anticoagulant therapy or the existence of an allergy to local anesthetics.