To begin diagnosing malignant or pre-malignant melanoma, a doctor visually inspects the questionable mole. The use of a dermatoscope, a device that illuminates the area to show the vascular network and underlying pigment is becoming more common. The next step is biopsy to confirm the diagnosis; usually removing the lesion or mole and a small bordering area for testing. Larger lesions require small punch biopsies that take samples from several areas.
To appropriately treat melanoma, it is vital to know the stage of the disease. Factors used in the staging of melanoma are:
- Breslow’s Depth: The millimeter measurement of the lesion.
- Clark’s Level: This measure indicates whether or not nearby skin is involved with the melanoma, whether ulceration has occurred, and whether the cancer has metastasized, or spread to other parts of the body.
To check for metastases, the following tests may be employed:
- Chest X-Rays
- CT Scans (Computed Tomography): An imaging technique that produces a three-dimensional representation from two dimensional x-ray images. In this way, the test highlights the structures that obstruct the path of x-rays. CT images can be manipulated to so that doctors can view the field from different angles.
- MRI (Magnetic Resonance Imaging): An imaging technique that uses a magnetic field to show the contrast between different tissues of the body. These images, too can be manipulated to show different views.
- PET Scans (Positron Emissions Tomography) or Combination PET/CT Scans: Another imaging device in which an image is reconstructed using computer analysis from a tracer substance introduced into the body. Newer versions of this test use PET and CT scanners in the same machine to create images simultaneously.
- LDH Test: A test that measures the enzyme Lactate dehydrogenase in the body. High levels of LDH in the liver often mean that the cancer has spread there.
Stages of Melanoma
- Stage 0: Melanoma in Situ, melanoma is contained in the original location and the primary lesion is less than 1 mm in size
- Stage I: Invasive melanoma, meaning larger skin structure involvement ( primary lesion approximately 1-2 mm in size) with ulceration in some cases
- Stage II: High Risk Melanoma, (primary lesion approximately 1-4 mm in size) with ulceration in some cases
- Stage III: Regional Metastasis, meaning either regional skin or lymph nodes are affected
- Stage IV: Distant Metastasis, meaning skin is affected distant from the original lesion or that organs are affected