What is the definition or description of: bone marrow biopsy?

Needle biopsy. : A bone marrow biopsy is taken from the pelvic bone. A coring needle is advanced into the bone, which allows one to extract a sliver of the bone marrow, the red part of the bone. It is cut and viewed under a microscope. A bone marrow aspirate, obtained with a syringe, is usually bone at the same time. These are done to diagnose blood problems or to check for tumors in people with known cancer.