Melanoma Diagnosis

Early and accurate diagnosis is essential to melanoma care and successful treatment. At Banner MD Anderson Cancer Center, we use the latest state-of-the-art technologies to diagnose and stage melanoma. In doing so, we can determine whether the cancer has spread and identify the most effective treatment for you.

Diagnostic Tests

If you have signs or symptoms of melanoma, your doctor will examine you and ask questions about your health, lifestyle and family history. If melanoma is suspected, a biopsy will be done.


Skin cancer cannot be diagnosed through observation alone. If a mole or pigmented area of the skin changes or looks abnormal, a tissue sample will be taken through biopsy for a pathologist to examine. Suspicious areas should not simply be shaved off or cauterized (destroyed with a hot instrument, an electrical current or a caustic substance). Rather, a biopsy should be performed first to determine if the area is malignant.

Your doctor may use one of the following biopsy methods:

  • Shave biopsy in which the top layers of skin area are shaved off using a surgical blade. This procedure is generally used to diagnose skin diseases not believed to be melanoma since the sample collected only includes the outer layers of skin and may not be thick enough to measure the depth of a melanoma. 
  • Punch biopsy removes a deeper layer of skin using a tiny round tool that is sharp enough to cut through all layers of the skin.
  • Incisional or excisional biopsy helps examine tumors that may have grown into the deeper layers of the skin by using a surgical knife to cut through all layers of the skin and remove a wedge or sliver of skin.
    • Incisional biopsy removes only a portion of the tumor
    • Excisional biopsy removes the entire tumor

If your skin usually scars when injured, the biopsy may leave a scar. For this reason, a biopsy on the face might be better performed by a surgeon or dermatologist who specializes in methods that minimize scarring.

Because melanoma can be difficult to diagnose, you should consider having your biopsy checked by a second pathologist. Testing for specific mutations on the tissue might be obtained by your doctor. Additionally, knowing the melanoma stage at diagnosis will help determine your treatment options.

What happens after a melanoma diagnosis?

After an early diagnosis of melanoma, imaging tests can help determine whether cancer cells have spread within the skin or to other parts of the body – even if it’s a non-invasive melanoma diagnosis. This may include such tests as:

  • Chest X-ray
  • Lymphoscintigraphy
  • Ultrasound
  • CT or CAT (computed axial tomography) scans
  • MRI (magnetic resonance imaging) scans
  • PET (positron emission tomography) scans