There are many subtypes of melanoma — the main four being superficial spreading melanoma, nodular melanoma, acral lentiginous melanoma and lentigo maligna melanoma — as well as rarer conditions like spitzoid melanoma, nevoid melanoma, desmoplastic melanoma, uveal melanoma or ocular melanoma, andr mucosal melanoma. Correctly diagnosing the subtype of melanoma is crucial because each may require a different treatment.
Determining whether a growth is benign or cancerous is a subtle process, requiring a trained eye and deep experience. A skin exam is usually the first test to diagnose all skin cancer, as most melanomas in the skin can be seen by the naked eye.
If an area on the skin looks abnormal, your doctor may order a skin biopsy, which involves removing tissue that appears abnormal and sending that tissue sample to a pathologist who can confirm if you have melanoma and what type and stage.
There are several types of skin biopsy:
- Shave biopsy is used to remove the abnormal growth using a razor blade.
- Punch biopsy utilizes a special round instrument to remove a circular tissue sample.
- Incisional biopsy involves removing a section of abnormal growth.
- Excisional biopsy involves removing all abnormal growth.
Usually, melanoma grows for a long time under the top layer of the skin without going into the deeper layer of skin. This allows time for skin cancer to be found early. Melanoma is easier to cure if it is found before it spreads. However, since screening has its risks, you may want to discuss them with your doctor before making a decision to be tested.