A core of bone, rather than an aspirate of liquid marrow, is collected using a large bore biopsy needle that is inserted and twisted to obtain a core biopsy sample from within the needle. The image* illustrates the body site where the bone marrow core biopsy is normally obtained.
The ideal bone marrow core biopsy sample, which depends on the reason for the bone marrow biopsy, should be approximately 1-2 cm in length for optimal evaluation of anemia. For evaluation of lymphoma or metastatic carcinoma, a larger core is desirable, usually bilaterally. In appearance, the core biopsy should be red, with grossly identifiable bone specks. What you do not want to see is a sample that is uniformly white or shiny. A solid white core biopsy usually indicates that cortical bone was sampled. A glistening sample may indicate that cartilage was sampled. However, metastatic carcinoma may present with a similar, glistening appearance.