What is it?
Malignant melanoma is the skin cancer with worst prognosis. It is a very dangerous tumor due to its high potential to metastasize, sending cancer cells to other organs, where they develop forming new tumors.
It originates from melanocytes, cells that produce the pigment that gives color to the skin. It may be originated from healthy skin or from pre-existing pigmented lesions: melanocytic nevus.
Occuring mostly in people with light skin (skin types I or II), melanoma can arise in skin areas not exposed to the sun but the greater number of lesions appear on skin usually exposed to solar radiation.
Characteristics and symptoms
Melanoma begins as a dark lesion that grows larger in depth or peripherally, changes its original color, shows pigmented spots around the initial lesion, ulcerates, bleeds or presents symptoms such as itching, pain or inflammation.
In the early stage, melanoma is confined to the outermost layer of skin, ideal time for the diagnosis and treatment because, at this location, it does not send tumor cells to other organs and the complete removal of the tumor has high cure rates. It is called melanoma in situ.
When melanoma is no longer flat, forming a raised lesion on the skin, this is a sign that it is also progressing in depth. The depth reached and the tumor thickness are the parameters that define its severity. The deeper and thicker the tumor is, the greater is the risk of metastasis to other organs.
The lesions of melanoma have characteristics which are easy to recognize using the ABCD criteria:
- Asymmetry: irregular shape
- Jagged Borders: irregular outer limits
- Different shades of Color
- Diameter greater than 6 mm
The photo below shows a melanoma in situ, in which the ABCD criteria can be clearly seen.
The most common presentation is superficial spreading melanoma. Slower-growing, horizontal, this type is readily identified, facilitating early treatment and cure.
Dark lesions that begin to acquire characteristics like those described above may be turning into a melanoma, especially if they are in areas of continuous sun exposure. The ultra-violet radiation from the sun can stimulate the transformation of melanocytic nevus into melanomas. Sun protection is the best way to prevent the emergence of malignant melanoma.
Moreover, any changes in an old nevus, such as: color change to darker or lighter, increasing in size, bleeding, itching, inflammation or the appearance of pigmented spots around the lesion, justifies a visit to a dermatologist for evaluation.
Other forms of presentation are the primary nodular melanoma, which has the fastest growing in depth, and lentigo malignant melanoma, flat tumor that occurs most often in people over 60 years of age and appears in areas of high sun exposure, especially the face.
Acral melanoma is a presentation in which the tumor arises in the feet or hands. A more rare presentation is the amelanotic melanoma, in which the tumor is not pigmented, making it more difficult to achieve clinical diagnosis.
The complete removal by surgery is the best treatment for malignant melanoma and should be performed as early as possible to avoid metastasis. The diagnosis and early treatment are fundamental keys for obtaining cure.
- Melanocytic nevus
- Basalcell carcinoma