Most patients have the bone marrow sampled from the pelvis.
You will lie on your stomach and the doctor will feel the bones at the top of your buttock. An area on your buttock will be cleaned with soap. A small needle is then inserted into your skin, and medicine is injected to numb the skin and underlying tissue in the area from which the sample will be removed. This causes some very brief stinging. A small cut will be made in the skin to allow the biopsy needle to be placed through the skin.