Stages of Melanoma
With melanoma, stages of the disease are categorized according to how thick the tumor is, how deeply the melanoma has invaded the skin, and whether cancer cells have spread to nearby lymph nodes or other parts of the body. Knowing the stages of the disease helps a doctor determine the appropriate type and amount of treatment a patient requires.
If a melanoma diagnosis is made, the doctor will need to learn the extent, or stage, of the disease before planning melanoma treatment.
Staging is a careful attempt to learn:
- How thick the tumor is
- How deeply the melanoma has invaded the skin
- Whether melanoma cells have spread to nearby lymph nodes or other parts of the body.
The doctor may remove nearby lymph nodes to check for cancer cells. (Such surgery may be considered part of the treatment, because removing cancerous lymph nodes may help control the disease.)
The doctor will also perform a careful physical exam and, if the tumor is thick, may also order:
- Chest x-rays
- Blood tests
- Scans of the liver, bones, and brain.
The stages of melanoma include:
- Stage 0
- Stage I
- Stage II
- Stage III
- Stage IV
In stage 0, the melanoma cells are found only in the outer layer of skin cells and they have not invaded deeper tissues. Stage 0 is also called melanoma in situ.
Stage I is divided into stages IA and IB.
In stage IA:
- The tumor is not more than 1 millimeter thick, with no ulceration
- The tumor is in the epidermis
- The tumor is in the upper layer of the dermis.
In stage IB:
- The tumor is not more than 1 millimeter thick, with ulceration
- The tumor may have spread into the dermis or the tissues below the skin
- The tumor is 1 to 2 millimeters thick, with no ulceration.