How Stage IV is Diagnosed
Step 1: Physical Examination
The patient should get a physical examination of the entire skin, lymph node areas, and organs.
Step 2: Tests to Make Certain
The doctor may order various other tests to confirm a diagnosis of melanoma and/or determine if or where the disease has spread:
X-ray. An x-ray is a picture of the inside of the body. For instance, a chest x-ray can help doctors determine if the cancer has spread to the lungs.
Blood tests. Blood levels of LDH may be tested to help determine if the cancer has spread.
Step 3: Additional Tests
Sometimes the following special scanning tests (similar to x-rays in that they provide special images of the inside of the body and require no surgery) may also be performed:
Ultrasound. An ultrasound uses sound waves to create pictures of the internal parts of the body, including collections of lymph nodes (called basins) and soft tissue.
Computed tomography (CT or CAT) scan. A CT scan creates a 3-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed view that shows any abnormalities or tumors.
Magnetic resonance imaging (MRI). An MRI is done with a special scanning machine that uses magnetic fields, not x-rays, to produce detailed images of the body.
Positron emission tomography (PET) scan. In a PET scan, a special fluid made of sugar is injected into the body, which can be seen by a special scanner. Cancer cells usually absorb sugar more quickly than normal cells, so they may light up on the PET scan. PET scans are often used in addition to a CT scan, MRI, and physical examination.
- In stage IV, the melanoma has spread to distant sites (metastasized).
- Because of this, doctors are not looking at thickness or lymph node involvement to make a diagnosis or prognosis.
- Instead, they're looking at the location, number, and size of the metastases and the serum LDH level.