Actinic keratosis
A precancerous condition of thick, scaly patches of skin.

Adjuvant therapy
Any treatment given after the first that is intended to increase the effectiveness of the first treatment.

Angioma
A benign tumor in the skin, which is made up of blood or lymph vessels.

Atypical mole
See dysplastic.

Basal cell carcinoma
Most common and least dangerous type of skin cancer; grows slowly and rarely spreads; usually on face in form of small round lump either red, pale, or pearly color; a type of skin cancer in which the cancer cells resemble the basal cells of the epidermis.

Basal cells
Cells that are found in the outer layer of skin. Basal cells are responsible for producing the squamous cells in the skin.

Benign tumor
Not a cancer; grows slowly; does not spread to other parts of the body like a cancer can.

Biopsy
Removal and microscopic examination of tissue from the body for the purpose of establishing a precise diagnosis. A biopsy is required to confirm a skin cancer diagnosis. During an excisional biopsy, the entire skin lesion is removed for microscopic examination. When an incisional biopsy is performed, a portion of the skin lesion is removed.

Cancer
Uncontrolled growth and spread of abnormal cells.

Chemical peels
Procedure often used to minimize sun-damaged skin, irregular pigment, and superficial scars. The top layer of skin is removed with a chemical application to the skin. By removing the top layer, the skin regenerates, often improving the skin's appearance.

Chemotherapy
Treatment with drugs to destroy cancer cells.

Clinical trial
A medical investigational study in which humans are observed and/or treated. A study may investigate a new treatment, prevention strategy, diagnostic method, screening procedure, or how to improve comfort and quality of life.

Collagen
A natural protein found in humans that forms connective tissue and provides strength, resilience, and support to the skin, ligaments, tendons, bones, and other parts of the body.

Cryosurgery
Freezing the tumor, which kills cancer cells.

CT scan
Computed tomography (CT), which is sometimes called a CAT scan, combines x-ray and computer technology to produce cross-sectional images of the body. Unlike an x-ray, which images bones, computed tomography can produce an image that shows everything in that area of the body, such as organs, bones, and blood vessels. These images can help detect cancer that has spread to an organ or a lymph node.

Cyst
A deep lesion that is filled with pus or other contents.

Cytokines
Proteins produced naturally in the body that act as "messengers" to initiate inflammatory and disease-fighting responses to viruses, bacteria, toxins, injury, and malignant processes. Cytokines are in use as anti-cancer medications.

Dermabrasion
Used to minimize small scars, minor skin surface irregularities, surgical scars, and acne scars. As the name implies, dermabrasion involves removing the top layers of skin with an electrical machine that "abrades" the skin. As the skin heals from the procedure, the surface appears smoother and fresher.

Dermatofibroma
Small, red or brown bumps in the skin.

Dermatopathologist
A medical doctor trained in both dermatology and pathology who uses this expertise to microscopically examine tissue in order to diagnose skin conditions, often providing expertise in diagnosing difficult cases.

Dermatoscopy
Also called surface microscopy, dermoscopy, and epiluminescence microscopy, this is a noninvasive technique used by dermatologists to examine pigmented and some non-pigmented lesions. The technique involves using a handheld microscope-like device that allows the dermatologist to see through the stratum corneum (bottom of the outermost layer of skin), permitting a detailed view of structures within the skin that are usually invisible to the unaided eye. Dermatoscopy can aid in early detection, help determine which skin lesions should be biopsied, and assist surgeons in determining how much normal-looking skin to remove.

Dermis
The middle layer of skin, which is made up of blood vessels, lymph vessels, hair follicles, sweat glands, collagen bundles, and fibroblasts.

Dermoid cyst
A benign tumor made up of hairs, sweat glands, and sebaceous glands.

Dysplastic
An alteration in size, shape, and organization of cells.

Electrochemotherapy
Uses a combination of chemotherapy and electrical pulses to treat cancer.

Epidermis
The outermost layer of the skin, containing basal cells and squamous cells.

Immunocompromised
An abnormal condition where one's ability to fight infection is decreased. This can be due to a disease process, certain medications, or a condition present at birth.

Immunotherapy
Treatment that repairs, stimulates, or enhances the body's own immune responses to fight established disease. It is sometimes combined with chemotherapy.

Inflammation
Redness, swelling, heat, and pain in a tissue due to chemical or physical injury, infection, or allergic reaction.

Interferon
Interferons are substances within the immune system that are produced in response to infection.

Interleukin
Interleukins activate the "killer" activities of specific white blood cells in the immune system. One specific interleukin, IL-2, helps the immune cells reproduce more quickly and is used to treat melanoma that has spread.

Keloids
Smooth, pink, raised, firm, fibrous growths on the skin that form secondary to injury.

Keratinocytes (Also called squamous cells)
The primary cell types found in the epidermis, the outer layer of skin.

Lymph nodes
Small organs that store cells that fight infection and other diseases. Lymph nodes are located throughout the body along the channels of the lymphatic system.

Malignant
Cancerous; the ability to grow and spread in an uncontrolled manner beyond the local confines of the tumor.

Malignant melanoma
A rare, but sometimes deadly, skin cancer that begins as a mole that turns cancerous.

Malignant tumor
Cancer that grows uncontrollably and can spread to other parts of the body; if left untreated it leads to death.

Margin
Refers to the amount of normal-appearing tissue to be removed along with the tumor during surgical excision. The thicker the tumor, the more normal-looking skin the surgeon removes. Margin is usually measured in centimeters. Surgical margins may be modified for an individual patient after considering medical or esthetic reasons. The main goal is complete removal of the cancer.

Melanin
The brown pigment which gives skin its color; the amount of this substance accounts for variations in skin color in different people and different races.

Melanocytes
Cells present in the epidermis that produce melanin (skin pigment).

Melanoma
Potentially fatal form of skin cancer; it can spread rapidly; usually curable if found early; cancer that begins in the melanocytes.

Metastasis
The spreading of disease from one part of the body to another. Both melanoma and squamous cell carcinoma metastasize. Melanoma most often spreads to the lymph nodes, liver, abdomen, lungs, bone, skin, heart, and brain.

Mohs micrographic surgery
A highly specialized surgical technique in which all remaining visible parts of a tumor are excised and skin is removed layer by layer and examined under a microscope while the patient is undergoing surgery. Skin continues to be removed until cancer is no longer detected.

Moles
Small skin marks caused by pigment-producing cells in the skin.

Nodule (also called papule)
A solid, raised bump.

Open biopsy
An incision is made in order to surgically remove tissue so that it may be examined under a microscope. This type of biopsy may be performed when a patient has melanoma and a lymph node near a melanoma feels hardened or enlarged. The lymph node in question is surgically removed and examined under a microscope to see if it contains melanoma cells.

Ozone layer
Ozone gas occurs naturally in the upper atmosphere where it forms a layer that protects the Earth's surface by absorbing a large amount of harmful UV radiation.

Photodynamic therapy
Uses a certain type of light and a special chemical to kill cancer cells.

Pre-cancerous
A term used to describe a condition that may or is likely to become cancer.

Primary tumor
The first appearance of a tumor. In skin cancer, there may be multiple primary tumors.

Punch grafts
Small skin grafts to replace scarred skin. A hole is punched in the skin to remove the scar, which is then replaced with unscarred skin (often from the back of the earlobe). Punch grafts can help treat deep acne scars.

Radiation therapy
Uses a radiation machine that emits x-rays to kill cancer cells and shrink tumors.

Recurrent tumor
A tumor that was treated but has returned.

Regional
Cancer that has spread beyond the site of the primary tumor to nearby lymph nodes and sometimes tissue/organs close to the primary tumor.

Risk factor
An attribute that increases the likelihood that something will occur. 

Sebaceous glands
Glands in the skin that secrete oil to the surface of the skin.

Skin cancer
There are three main types: basal, squamous, and melanoma. Skin cancer rates in Florida are one of the highest in the country.

SPF
Sun Protection Factor (See definition below.)

Squamous cell carcinoma
Skin cancer that forms in the flat, scale-like skin cells of the epidermis called the squamous cells. It accounts for approximately 16% of all skin cancers. This cancer is highly treatable, but it can metastasize and cause death.

Squamous cells
The primary cell types found in the epidermis, the outer layer of skin.
Stage
How far the cancer has advanced. The staging process determines whether the cancer is confined to the primary tumor or if it has progressed to the lymph nodes or distant organs.

Subcutis
The deepest layer of skin; also known as the subcutaneous layer.

Sun Protection Factor (SPF)
SPF indicates the degree of protection the sunscreen provides. A sunscreen with an SPF of 4 provides the least protection; sunscreen with an SPF of at least 15 provides the most protection. SPF is based on how long unprotected skin takes to burn when exposed to artificial sunlight.

Sunscreen
A substance that blocks the effects of the sun's harmful rays; using sunscreen can reduce the risk of skin cancer.

Topical chemotherapy
Chemotherapy given as a cream or lotion placed on the skin to kill cancer cells.

Tumor
An abnormal growth of tissue on or in the body formed by a collection of cells. A tumor may be benign (not a cancer) or malignant (a cancer).

Ulceration
A break in the surface of a skin cancer tumor, which is often only seen under the microscope. When such a break occurs, the tumor is said to be "ulcerated."

Ultraviolet radiation (UV radiation)
The sun's harmful rays, which can damage the skin and cause melanoma and other types of skin cancer.. UV radiation is made up of three parts:

• UVA: originally believed to be harmless but now believed to cause skin damage.
• UVB: causes skin damage, sunburn, and skin cancer.
• UVC: none reaches the Earth's surface; it is all absorbed by the ozone layer.

Wart
A non-cancerous skin growth caused by a virus.