To diagnose bone cancer, a physician will take a patient’s medical history and perform a complete physical examination. Blood tests may be ordered to measure the level of alkaline phosphase. This enzyme, alkaline phosphase, is often present in high amounts when the cells that form bone tissue are extremely active. A high level of alkaline phosphase may indicate bone cancer because levels increase when disease or a tumor cause higher production of abnormal bone tissue. However, high levels can also be found when children are growing and in individuals of all ages when broken bones are mending and in certain liver abnormalities. For this reason, the test alone is not enough for diagnosis.

A variety of imaging tests may be ordered to detect bone cancer. These tests include:

• X-rays. An x-ray is a painless test in which an image is created of part of the body by using low doses of electromagnetic radiation that are reflected on film or fluorescent screens. X-rays may be ordered to show the location, size and shape of a bone tumor. The majority of bone cancers can be detected with x-rays of the bone. Often, a radiologist can determine if the tumor is malignant by its x-ray appearance. A chest x-ray can reveal if bone cancer has spread to the lungs.
  
  
• CAT scan or CT scan. Computed axial tomography allows for multiple x-rays to be taken from different angles around the patient. A computer than analyzes the data and produces detailed cross-sectional images of the patient’s body. CAT scans may be used to guide a biopsy needle into a lesion located deep in the body. The procedure, known as a CT-guided needle biopsy, is used to obtain a sample of tissue for analysis.

• MRI. Magnetic resonance imaging uses a powerful magnetic field to create images of structure and organs within the body allowing a computer to produce clear cross-sectional or three-dimensional images. In some cases, a contrast medium (dye) may be used to more clearly define structures. MRI uses no radiation and may give better visualization of bone and nerve tissue than other imaging tests.
  
  
• Bone scan. A tiny amount of radioactive isotope is injected into a vein and allowed to travel to the bones. The body is then scanned with an external scanner. This test may be ordered to show if the cancer has spread to other bones, or to reveal the extent of damage the cancer has caused to a bone. It can also find metastases (the spread of cancer cells to distant areas of the bone) earlier than regular x-rays.
  
  
• PET scan. In positron emission tomography, the patient receives an injection of glucose (sugar) containing a small amount of radioactive material. Once in the body, the radioactive glucose is preferentially absorbed by the cancer cells. A camera then scans the patient and detects where the radioactive glucose was absorbed. Cancerous cells appear as “hot spots” on the image. This test may be used to determine if and where cancer metastasized in the body.

Although patient symptoms, a physical examination, imaging tests and blood tests may suggest that a patient has bone cancer, biopsies are usually required to diagnose bone cancer. A biopsy can determine the type of cancer and classify it as primary or secondary bone cancer. The procedure involves removing a sample of the tumor cells or tissue for examination under a microscope. Needle biopsies and surgical bone biopsies are two procedures used to diagnose bone cancer. This additional testing allows a physician to eliminate bone infections and other diseases as the cause of the problem.

After a diagnosis has been confirmed, the disease will be staged. Staging is the process of determining how far the cancer has spread and is necessary for a physician to plan treatment.