Types of Malignant Melanoma

Dermatologists recognize four main types of malignant melanoma: superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, and acral lentiginous melanoma. They also recognize two main subtypes.

Superficial Spreading Melanoma

• Superficial spreading melanoma accounts for 7 out of 10 melanoma cases. It begins as a tiny spot with irregular borders, and it can appear as black, brown, blue, red, white, and other colors. As the melanoma progresses, it may change colors, and it may also become itchy or inflamed.

Nodular Melanoma

• Out of all the types of melanoma, nodular melanoma is the most aggressive. It is usually dark colored, such as a black or brown. Unlike some other melanomas, nodular melanoma spreads downward (into the skin) quicker than outward (atop the skin), which can make it difficult to detect. Persons over the age of sixty are particularly at risk.

Lentigo Maligna Melanoma

• Lentigo maligna melanoma generally grows on sun-damaged skin. Its patchy brown colors may resemble an age spot or a sun spot, particularly a harmless type of discoloration called a lentigo simplex. Consequently, lentigo maligna may grow for years until it darkens in color and develops more irregular borders. Before it actually turns cancerous, lentigo maligna melanoma is also called a "Hutchison's freckle."

Acral Lentiginous Melanoma

• Acral lentiginous melanoma accounts for half of all melanoma cases in African-Americans and Asians. It is also called "hidden melanoma" because of where it forms: on soles and palms, inside the mouth or nose, or even beneath a fingernail or toenail. During its early stages, acral lentiginous melanoma often looks like an odd-shaped tan or a nail streak.

Subtypes

• The two subtypes of malignant melanoma are relatively uncommon. The first, amelanotic melanoma, appears like reddish or pinkish lump, and the second, desmoplastic neutrotrophic melanoma, looks like a colorless scar.