Defining Skin Cancer

Words like dysplastic nevus and metastasis are not words that you use every day and can be worrisome when you hear them used in your dermatologist’s office.

To help you navigate some of the complex terms associated with skin cancer, we’ve compiled an easy-to-follow glossary of definitions.

Actinic keratosis (AK) – The most common type of precancerous skin lesion. Actinic keratoses appear on skin that has been frequently exposed to ultraviolet (UV) radiation from the sun or to artificial sources of UV light, such as indoor tanning beds. They typically look like crusty or scaly skin patches.

Acral lentiginous melanoma – A rare type of melanoma that often arises on the palms of the hands, the soles of the feet or under the nails. The most common type of melanoma diagnosed in people of color, it is an especially aggressive form of the disease that is not caused by ultraviolet exposure.

Atypical moles– Unusual-looking benign moles, also known as dysplastic nevi, these lesions often resemble melanoma. Like melanoma, they are often over 6 mm (1/4”) in diameter, are asymmetrical and have irregular borders and more than one color. People with atypical moles are at increased risk of developing melanoma, either directly in the moles or elsewhere on the body.

Basal cell carcinoma (BCC) – The most common form of skin cancer, these tumors develop in the skin’s basal cells, which line the deepest layer of the epidermis – the outermost layer of your skin. Caused mainly by a combination of cumulative and intense, occasional sun exposure, BCCs often look like open sores, red patches, pink growths, shiny bumps or scars. BCCs rarely spread to other parts of the body, but if not caught early, they can be extremely destructive and even disfiguring where they occur, sometimes costing someone an eye, ear or nose.

Benign – When you hear this, it’s usually good news. Benign tumors are noncancerous growths and do not spread to other parts of the body. Depending on the nature of the benign tumor – whether it is cosmetically acceptable, interferes with function or potentially can turn cancerous – it may or may not be necessary to remove.

Biopsy – A procedure done in a dermatologist’s office to study a suspicious growth at the cellular level. The physician removes a small sample of the lesion and has it examined in the lab to determine what kind of growth it is and whether it is cancerous or benign.

Dermis – Did you know skin is the heaviest organ in the body, weighing twice as much as the brain? The dermis is the second major layer of skin, containing our blood capillaries, nerve endings, sweat glands, hair follicles and other structures. Here are 10 surprising things about your skin.

Dysplastic nevus – Also known as an atypical mole, a dysplastic nevus is am unusual-looking mole that has irregular features under the microscope. While benign, this type of mole is important to keep an eye on. Individuals with atypical moles are at increased risk for melanoma, a dangerous skin cancer.

Epidermis – As humans, we shed a lot! Your skin renews itself every 28 days with an average of 40,000 dead skin cells being shed per minute. The outermost layer of the skin, the epidermis is made up of mostly scale-like cells known as squamous cells. Most skin cancers begin in the epidermis.

In situ – Latin for “in place,” this typically means good news since it refers to a cancerous but noninvasive tumor that has not penetrated beyond the epidermis into the dermis. But even skin cancers diagnosed in the early stages can be painful or cause scarring and may require multiple treatments. In situ skin cancers can also become invasive if not removed in a timely way.

Invasive – An invasive skin cancer has penetrated beyond the epidermis into the dermis and is growing into surrounding, healthy tissue. Invasive skin cancers should be removed promptly, and tests need to be done to see if further treatments are called for.

Lesion – A skin lesion is an abnormal mark or growth on the skin. It can range from a blister, birthmark, scar or benign nodule to a serious skin cancer.

Lymph nodes – These small, bean-sized glands throughout the body, part of the lymphatic system, are major sites for the lymphocytes and other white blood cells, which engulf and destroy foreign particles such as bacteria. Important for proper immune functioning, the lymphatic system delivers nutrients throughout the body via the lymphatic fluid and acts as a filter by carrying waste products to the bloodstream and ultimately out of the body. However, cancer cells can also use this system to travel throughout the body, attacking distant sites and organs.

Malignant – Another word for cancerous. Malignant tumors consist of abnormal cells that divide without control and can invade nearby healthy tissues.

Melanocyte – Specialized skin cells that produce the protective skin-darkening pigment melanin. Exposure to UV radiation damages melanocytes, causing sunburns and tanning, which can lead to melanoma.

Melanoma – A cancer that arises from damaged or defective melanocytes. One of the most dangerous forms of skin cancer, melanoma is often triggered by the kind of intense, intermittent sun exposure that leads to sunburn.

Merkel cell carcinoma (MCC) – A rare type of skin cancer that usually appears as a flesh-colored or bluish-red nodule, often on the face, head or neck. If not caught very early, MCC is an exceptionally dangerous skin cancer.  Like most skin cancers, it is most often caused by sun exposure. A specific type of virus called a polyomavirus is also involved in the majority of MCCs.

Metastasis – The spread of cancer cells from a primary tumor to new areas of the body (often by way of the lymph system or bloodstream). Once a tumor has metastasized to the lymph nodes, it is considered a stage III cancer. Once it has metastasized to distant body sites and organs, it is considered stage IV.

Mole – A pigmented spot, mark or growth on the body. Almost everyone has at least one mole, if not multiple moles. They occur when cells in the skin grow in a cluster. Most moles are benign, but those that exhibit any abnormal, atypical or changing features are typically monitored closely by dermatologists to ensure they are not cancers.

Squamous cell carcinoma (SCC) – The second most common form of skin cancer, these tumors develop from abnormal squamous cells, which compose most of the epidermis. SCCs often look like scaly red patches, open sores, warts or elevated growths with a central depression. They may crust or bleed. They can become disfiguring and sometimes deadly if not caught early.

Staging – Staging is a numerical system used in cancer diagnosis to sum up how far a cancer has advanced. For example, stage I means the cancer is small and contained, with no high-risk features; in stage II, the cancer still has not spread, but is large or has other features that put it at high risk of spreading to the nearby lymph nodes; in stage III, the cancer has spread to the lymph nodes or has gone beyond the primary tumor en route to the lymph nodes; and in stage IV, it has spread to distant body sites or organs. Any tumor beyond stage I brings increased risk, and stage III and IV tumors can be life-threatening. The staging system was put in place to help doctors and other caregivers home in on the patient’s prognosis and the best treatment options.

Subungual melanoma – Subungual melanoma is a rare, potentially deadly form of melanoma that is more common in people of color. It appears as a brown or black streak under a fingernail or a toenail, but often increases in size.

Tumor – A mass in the body caused by abnormal growth and clustering of tissue. Tumors can be either benign or malignant, and often may require a biopsy or other medical testing to determine which it is and exactly what it is.