The basic types of melanoma are superficial spreading melanoma, lentigo maligna, acral lentiginous melanoma and nodular melanoma, as listed by the Skin Cancer Foundation. Rare types of melanoma include amelanotic melanoma, melanoma of the eye, melanoma of the vulva and vaginal melanoma, according to Cancer Research UK.
Superficial spreading melanoma, lentigo maligna and acral lentiginous melanoma are in situ, which means that they only occupy the top layer of the skin and may sometimes become invasive, as explained by the Skin Cancer Foundation. Nodular melanoma is invasive from the start and is more serious because it penetrates deeper into the skin and may spread to other parts of the body.
Superficial spreading melanoma is the most common type of melanoma because it accounts for about 70 percent of all melanoma cases, according to the Skin Cancer Foundation. It is common in young people and grows on the skin's top layer for a long time before penetrating deeper.
Lentigo maligna is common in the elderly, and it arises on damaged and chronically sun-exposed skin, as detailed by the Skin Cancer Foundation. Acral lentiginous melanoma spreads superficially before advancing more deeply into the skin. However, it advances faster and is more common in Asians and African Americans.
Nodular melanoma is invasive from its onset, and it is the most aggressive type of melanoma, as the Skin Cancer Foundation explains. Amelanotic melanomas have little or no color, but they are occasionally pink or red, according to Cancer Research UK. The lack of color makes them more difficult to discover and diagnose.