Types of Skin Cancer

There are many different types of skin cancer, some more serious than others. Three types of skin cancer account for nearly 100% of all diagnosed cases. Each of these three cancers begins in a different type of cell within the skin, and each cancer is named for the type of cell in which it begins.

The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands and arms. Basal cell rarely spreads beyond the skin. Squamous cell is usually confined to the skin but can metastasize (spread through the body).

The third type melanoma is the most invasive and dangerous type. Not all changes in your skin are cancer, but you should see your doctor if you notice changes in your skin.

Basal cell carcinoma

Basel cell is the most common skin cancer. Yet, it is very rarely a threat to life. About 80% of all skin cancers are basal cell carcinoma, a cancer that develops in the basal cells - skin cells located in the lowest layer of the epidermis. Basal cell carcinoma typically affects people of fair complexion who have had a lot of sun exposure, or repeated episodes of sunburn. The tendency to develop Basal cell carcinoma may be inherited.

Basal cell can take several forms. It can appear as a shiny translucent or pearly nodule, a sore that continuously heals and then re-opens a pink slightly elevated growth, reddish irritated patches of skin, or a waxy scar. Most Basal cell carcinomas appear on skin with a history of exposure to the sun, such as the face, ears, scalp, and upper trunk. These tumors tend to grow slowly and can take years to reach ½ inch in size.

While these tumors very rarely metastasize (cancer spreads to other parts of the body), dermatology community encourages early diagnosis and treatment to prevent extensive damage to surrounding tissue.

Squamous cell carcinoma

Squamous cell carcinoma accounts for about 16% of diagnosed skin cancers. This cancer begins in the squamous cells, which are found in the upper layer of the epidermis. Squamous cell carcinoma typically affects people of fair complexion. Lesions develop in areas that have been exposed to the sun over a long period.

Squamous Cell Carcinomas vary in size from a few millimeters to several centimeters in diameter. Sometimes they grow to the size of a pea or larger in a few weeks, though more commonly they grow slowly over months or years. They may be tender.

It most often appears as a crusted or scaly area of skin with a red inflamed base that resembles a growing tumor, non-healing ulcer, or crusted-over patch of skin. While most commonly found on sun-exposed areas of the body, it can develop anywhere, including the inside of the mouth and the genitalia. Squamous cell carcinoma may arise from actinic keratoses, which are dry, scaly lesions that may be skin-colored, reddish-brown or yellowish-black. If not treated early, squamous cell carcinoma may metastasis (spread).

Melanoma

Melanoma is a serious skin cancer, which is curable if detected early. Sometimes called cutaneous melanoma or malignant melanoma, melanoma grows from pigment cells (melanocytes) in the outer layer of the skin and mucous membranes (epidermis). Melanoma is a more serious type of cancer than the more common skin cancers, basal cell cancer or squamous cell cancer, which begin in the basal or squamous cells of the epidermis.

Melanoma accounts for about 4 percent of all diagnosed cancers. It usually occurs in adults, but it may occasionally be found in children and adolescents. Men most often get melanoma on the trunk (the area of the body between the shoulders and hips) or on the head or neck; women most often get melanoma on the arms and legs.

Melanoma is the most lethal form of skin cancer as it can rapidly spread to the lymph system and internal organs. (Lymph nodes are small, bean-shaped structures that are found throughout the body; they produce and store infection-fighting cells.) In the United States alone, approximately one person dies from melanoma every hour.

With early detection and proper treatment, the cure rate for melanoma is about 95%. Once its spreads, the prognosis is poor. You should see your doctor if you have any of the following warning signs of melanoma change in the size, shape, or color of a mole; oozing or bleeding from a mole; or a mole that feels itchy, hard, lumpy, swollen, or tender to the touch. Melanoma most often develops in a pre-existing mole or looks like a new mole, which is why it is important for people to know what their moles look like and be able to detect changes to existing moles and spot new moles.

ABCD’s of Melanoma

Asymmetry – One half doesn’t look like the other half Borders – Uneven, notched or fuzzy Color – More than one color or shade Diameter – Greater than ¼ of an inch

If you have signs of skin cancer, your doctor will examine your skin carefully. If a mole or pigmented area doesn't look normal, your doctor will cut it out (called local excision) and look at it under the microscope to see if it contains cancer. This is usually done in a doctor's office. It is important that this biopsy is done correctly.