12 NCCN Guidelines for Patients ® : Melanoma, 2018 1 Melanoma basics Types of melanoma Types of melanoma Melanoma may be found anywhere in the body. The most common area is the skin. Other rare types include mucosal melanoma and uveal melanoma. Mucosal melanoma may occur in the mucous membranes that line the sinuses, oral cavity, anus, vulva, vagina, GI ( g astro i ntestinal) tract, and other areas of the reproductive tract. Uveal melanoma occurs in the uveal tract of the eyes. The uveal tract is the middle layer of the eye that contains the choroid, ciliary body, and iris. This book focuses on melanoma that starts in the skin. Below is a list of the four major types of melanoma skin cancer. Learning the unique features of each can help you recognize these features, and may allow for earlier detection. These features include color, shape, location, and growth pattern. Superficial spreading melanoma Superficial spreading melanoma is the most common type of melanoma. It is also the most common type diagnosed in younger people. It usually looks like a brown-black stain that is spreading from a mole. But, most melanomas do not develop from a pre-existing mole. See Figure 5 . A mole is a spot on the skin formed by a cluster of melanocytes—cells that make melanin to give skin its color. This type of melanoma normally occurs on skin that is sometimes exposed to high levels of sunlight or artificial UV ( u ltra v iolet) light (such as from tanning beds), including the trunk and legs. Nodular melanoma Nodular melanoma grows more quickly into the dermis than other types of melanoma. It tends to be deeper than other types of melanoma at the time it is found. The dermis is the second layer of skin, located under the epidermis. Once in the dermis, it can spread to other tissues. Nodular melanoma looks like a dome-shaped bump and feels firm. It tends to ulcerate and bleed more often than other types of melanoma. Lentigo maligna melanoma Lentigo maligna melanoma is the slowest growing type of melanoma. It tends to develop in sites of chronic sun exposure in older adults. It is not generally associated with having a lot of moles. When it begins, it looks like a dark, flat stain with an uneven border and may be mistaken for a harmless sunspot. This type of melanoma usually occurs on chronically sun-exposed areas of the face, ears or arms. Acral lentiginous melanoma This type of melanoma is not related to UV light exposure. It occurs on the palms of the hands or soles of the feet, including fingernails and toenails. It can appear as a dark spot, like a bruise that doesn’t go away. In a nail, it can look like a dark stripe. Acral lentiginous melanoma is the least common type of melanoma. But, in people with darker-colored skin such as Asians, Hispanics, and African Americans, it is the most common type of melanoma, since sun- related melanoma is less frequent. Signs and symptoms Often, the first sign of melanoma skin cancer is a mole or spot on the skin that looks abnormal—not normal. It may present as a new “mole” or an existing mole that has changed over the past few weeks or months. But, most melanomas do not arise from existing moles. Finding melanoma before it grows deep in the skin is important. This is because deeper melanomas are more likely to have spread to other parts of the body. Treatment is more likely to cure melanoma if it has not spread.