The doctor is in… by Dr. Jim Vizcayno

MELANOMA is a type of skin cancer. It begins in certain cells in the skin called melanocytes. Each year more than 53,600 people in the United States find out they have melanoma. To understand melanoma, it is helpful to know about the skin and about melanocytes, what they do, how they grow and what happens when they become cancerous.

THE SKIN

The skin is the body’s largest organ. It protects us against sunlight, injury and infection. It helps regulate body temperature, stores water and fat, and produces Vitamin D. The skin has two main layers: the outer epidermis and the inner dermis.

The epidermis is mostly made up of flat, scalelike cells called squamous cells. Round cells called basal cells lie under the squamous cells in the epidermia. The lower art of the epidermia also contains melanocytes.

The dermis contains blood vessels, lympathic vessels, hair follicles, and glands. Some of these glands produce sweat, which help regulate body temperature, and some produce sebum, an oily substance that helps keep the skin from drying out. Sweat and sebum reach the skin’s surface through tiny openings called pores.

Melanoma occurs when melanocytes become malignant. The disease is also referred to as cutaneous melanoma or malignant melanoma. (Another type of melanoma, ocular melanoma, develops in the eye).

Melanoma can occur on any skin surface. In men, it is often found on the trunk (the area from the shoulders to the hips) or the head and neck. In women, melanoma often develops in the lower legs or the trunk. Melanoma is rare in black people and others with dark skin. When it does develop in dark-skinned people, it tends to occur under the fingernails or toenails, or on the palms or soles. Melanoma affects people of all age groups, but the chance of developing this disease increases with age.