This is a number that ranges from 1–5 (written in Roman numerals I–V) to describe how deeply the cancer has penetrated the skin. Clark level 5 (V) is the deepest level of invasion.
Ulceration is the breakdown of the top layer of skin over the melanoma. The presence or absence of ulceration is used to help determine the stage of melanoma. The presence of ulceration indicates a more rapidly growing melanoma.
This describes how quickly the melanoma cells are dividing. Higher mitotic rates (e.g. greater than 5 per mm²) indicate faster growing melanoma and are associated with a worse prognosis.
Your pathology report may describe the presence or absence of melanoma cells at the edges or deepest part of the sample (surgical margins). If these margins are positive (melanoma cells are present) more surgery may be needed.
Lymph node pathology report
If you have had a sentinel node biopsy, or you have had lymph nodes removed during surgery, the pathology report you receive after these procedures will record information about the number of nodes retrieved, the number of nodes containing melanoma and whether the melanoma has breached the node (called extra-nodal spread). The greater the number of lymph nodes containing melanoma, the poorer the prognosis. Extra-nodal spread is also associated with a poorer prognosis.
Stages of melanoma
Staging a melanoma provides a description of its size and whether it has spread to other parts of the body. The stage of your melanoma helps to guide your treatment.
There are three ways to stage a melanoma, and all patients will undergo at least two of these:
- Microstaging – A histopathologist looks closely at tissue under a microscope using special dyes and techniques to look for speciﬁc features that will help inform how far the disease has spread.
- Clinical staging – The lymph node groups that relate to the location of the melanoma are carefully examined to for any evidence of spread, usually seen by enlarged lymph nodes.
- Staging after investigation – This involves the use of imaging scans to see inside the body, including CT, MRI, and PET scans.
Melanoma is staged as O, I, II, III or IV. It can also have a substage (a-d). The following table outlines the different
stages of melanoma, and relevant treatment pathways: