A bone marrow biopsy, in which tissue is taken from the center of a bone and examined under a microscope, can help determine whether a cancer has spread to the bone marrow. Sometimes surgery may be needed to determine the cancer's stage. An analysis of lymph nodes removed from the armpit during a mastectomy helps determine how far breast cancer has spread and whether postsurgical therapy is needed. Ultrasound scanning is a painless, noninvasive procedure that uses sound waves to show the structure of internal organs. It's helpful for identifying and determining the size of certain cancers, particularly of the kidneys, liver, pelvis, and prostate.
Doctors also use ultrasound to guide the removal of tissue samples during a needle biopsy.
A lymphangiogram is a test in which dye is injected into the feet and followed with x-rays as it flows upward. The test helps identify abnormalities in the abdominal lymph nodes. Although uncommonly done since the advent of CT imaging, lymphangiograms continue to have value in staging Hodgkin's disease and testicular cancer. With this procedure, a very powerful magnetic field generates exquisitely detailed anatomical images. It is of particular value in detecting cancers of the brain, bone, and spinal cord.