Melanoma

Superficial spreading melanoma is the most common type of melanoma. As the name suggests it begins more superficial in the skin growing as a flat lesion. It will initially grow in the top layers of the skin in a horizontal direction but if left long enough it will begin to grow down vertically into the deeper layers of the skin. Clinically these lesions have a variable presentation. They can be tan, brown, red, black, white, blue, or commonly multicolored. 

Nodular melanoma is the second most common type of melanoma. Unlike the superficial spreading type, nodular melanomas begin with a vertical growth phase. Starting in a downward growth pattern makes this type more dangerous. Clinically they will present as a nodule or bump that is brown, black, red, blue, white, pink, or a combination of colors. They will often bleed easily and become ulcerated if bumped. 

Lentigo Maligna Melanoma typically occurs on chronically sun-damaged areas of the head and neck. This type is more commonly seen in the sixth and seventh decades of life. Lentigo Maligna follows a slow growth pattern typically in a radial or horizontal direction. If left untreated for many years it can start to grow in a vertical invasive direction. Clinically it presents as a flat or slightly raised skin lesion with multiple colors including brown, tan, and black. 

Acral lentiginous melanoma is the most common type of melanoma in dark-skinned and Asian persons. It is important to note that this type can occur in all skin types but is just more common in darker skin types. Clinically it presents as a brown/black flat or slightly elevated skin lesion affecting the palms and soles. It can also present around the nail unit of the hands and feet. This can be a dangerous type of melanoma as it can often go undetected on the bottom of the foot.