It appears as a thin superficial lesion with variegated color and well-circumscribed but irregular margins. This type of skin cancer evolves over time and can reach a diameter of 25 mm with possible nodular areas. At this stage the prognosis is poor.
Nodular Melanoma
Nodular Melanoma has a frequency of 10 to 15% and is usually found in men around 50 - 60 years. It's characterized by the appearance of a lump that grows quickly in about 6 to 18 months. This type of cancer can affect all parts of the skin and it doesn't have symptoms. Sometimes the diagnosis is difficult because it doesn't show the typical tumoral color.
Acral Lentiginous Melanoma
This is the most rare type of melanoma skin cancer. Usually appears as a variously pigmented patch with irregular edges and increases in size over time. It mostly occurs at the ends of the limbs, in hands and feets and it's mostly found in dark-skinned men. Resembles the lentigo maligna melanoma and the superficial spreading melanoma. It spreads superficially for a relatively long time before it penetrates into deeper levels of the skin.