Play 0:00 A-DE-IJ-OP-Z A-D Return to top Acral lentiginous melanoma The least common form of melanoma, or malignant skin tumor, which usually develops on the palms, soles of the feet, under the nails, or in mucous membranes that line the mouth, nose, and female genitals. Actinic cheilitis A form of actinic keratosis that most often occurs on the lower lip and causes it to become dry, cracked, scaly, and pale or white. Actinic keratosis (AK) (solar keratosis) A precancerous skin condition that has a rough, scaly, slightly raised growth that varies in color. Adjunctive therapy Any treatment that is added to the main treatment, such as radiation therapy after surgery. Adjuvant therapy Treatment used after the main treatment to increase the chances of a cure. These may include chemotherapy, radiation therapy, hormone therapy, or biological therapy. Anesthetic A drug that causes loss of feeling or awareness. Asymmetry Unevenness, lop-sidedness, or irregularity. Basal cells Small, round skin cells that are formed in the top layer of the skin, or epidermis. Basal cell carcinoma (BCC) A type of non-melanoma skin cancer that develops in the small, round basal cells found in the outer layer of the skin. It is the most common form of skin cancer. Basal cell nevus syndrome (Gorlin’s syndrome) A rare, inherited disease that may include a number of abnormal conditions, such as developing several basal cell carcinomas, small pits on the palms and soles, and jaw cysts. Benign A growth or condition that is non-cancerous and not life threatening. Biopsy The removal of tissue samples from the body so that they can be viewed under a microscope to make a diagnosis. Bowen’s disease Skin disease that consists of scaly or thickened patches, which often occur on sun-exposed areas of the skin, in the genital area related to human papillomavirus (HPV) infection, or by overexposure to the chemical arsenic. Cancer A term for diseases in which abnormal cells divide without control. Carcinoma Cancer that begins in the skin or in tissues that line or cover internal organs. Chemotherapy The use of chemical-based drugs for the treatment of cancer and other diseases. Computed tomography (CT) scan A series of detailed pictures of areas inside the body that are created by a computer attached to an x-ray machine. Cryosurgery A procedure in which tissue is frozen to destroy abnormal cells. Curettage Removal of tissue with a spoon-shaped surgical instrument. Curette A spoon-shaped surgical instrument with a sharp edge. Cystic basal cell carcinoma A rare form of basal cell cancer in which the nodules or lumps are filled with a gelatin-like fluid. Dermatoscope An instrument to examine the skin that utilizes a bright light and a magnifying lens. Dermis One of the three main layers of tissue that make up the skin and lies directly underneath the epidermis, or outer layer of skin. Dermoscopy (dermatoscopy, epiluminescence microscopy (ELM), surface microscopy) A procedure that uses a specially lighted magnifying lens to look at spots on the skin more clearly. Dysplastic nevi Atypical or abnormal moles. E-I Return to top Electrodesiccation and curettage A surgical procedure, used to remove superficial skin cancers, in which the growth is removed with a curette and an electric current is delivered to the area to control bleeding and destroy any residual cancer cells. Epidermis The thin, outermost layer of the skin. Epiluminescence microscopy (ELM) (dermoscopy, dermatoscopy, surface microscopy) A procedure that uses a specially lighted magnifying lens to look at spots on the skin more clearly. Excisional biopsy A surgical procedure in which an entire lump or suspicious area is removed for examination and diagnosis. Fibroepithelioma basal cell carcinoma A rare form of basal cell cancer, which consists of reddish lesions that appear on the back. Fibrous Consisting of fibers or in elongated threads. Follicle A sac or pouch-like cavity formed by a group of cells. In the skin, one follicle contains one hair. Gland An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk. Gorlin’s syndrome (basal cell nevus syndrome) A rare, inherited disease that may include a number of abnormal conditions, such as developing several basal cell carcinomas, small pits on the palms and soles, and jaw cysts. Human immunodeficiency virus (HIV) The virus that causes AIDS. Human papillomavirus (HPV) A virus that causes abnormal tissue growth (warts) and is often linked with some types of cancer. Hyperthermic isolated limb perfusion chemotherapy A cancer treatment where the drugs are heated and then injected into the bloodstream or into the part of the body that has the cancer, for example the arm or leg. Immune system The group of organs and cells that defend the body against infection or disease. Immunotherapy Treatment to stimulate or restore the immune system’s ability to fight infections and other diseases. It can be used to lessen side effects that may be caused by some cancer treatments. Immunotherapy is also known as biological therapy. Incisional biopsy A surgical procedure where a section of a lump or suspicious area is removed for examination and diagnosis. Intravenous (IV) chemotherapy Drugs that treat cancer, which are given directly into a vein. Ionizing radiation A dangerous type of energy made by x-rays, radioactive substances, and other sources. At high doses, ionizing radiation can lead to health risks, including cancer. J-O Return to top Keratin A type of fibrous protein produced by keratinocytes. The skin, hair, and nails are made of keratin. Keratinocytes Cells in the epidermal or outer layer of the skin that produce the fibrous protein called keratin. Keratoacanthoma A dome-shaped, cancerous, and rapidly growing skin tumor, which usually occurs on sun-exposed areas of the skin and is treated like a squamous cell carcinoma. Lentigo maligna melanoma A type of melanoma that usually occurs in the elderly and is most common in sun-damaged skin on the face, neck, arms, and legs. Lesion An area of abnormal tissue change. Leukoplakia A white patch that may develop on mucous membranes, such as the cheek, gums, or tongue, and may become cancerous. Local anesthetic A drug, usually injected, that causes loss of feeling or awareness to a specific part of the body. Lymph node One of several bean-shaped organs in the lymphatic system found throughout the body, whose main function is to fight infection. Lymph node biopsy A test in which a lymph node or a piece of a lymph node is removed for examination under a microscope for signs of infection or disease, such as cancer. Lymph node dissection (lymphadenectomy) A surgical procedure to remove one or more lymph nodes in order to examine for cancer. Lymphoma Cancer that develops in cells of the lymphatic system. Lymph vessel A thin-walled structure that carries tissue fluid to the lymph nodes. Magnetic resonance imaging (MRI) A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. Margin The edge or border of the tissue removed in cancer surgery. Melanin A substance that gives the skin its color and also provides protection against the sun’s harmful rays. Melanocytes Cells in the skin and eyes that produce and contain the coloring called melanin. Melanoma An aggressive form of skin cancer that develops in melanocytes, the cells that produce the skin’s color. Metastasis The spread of cancer cells from one part of the body to another. Mohs surgery A surgical procedure, used to treat skin cancer, in which individual layers of cancerous tissue are removed and examined under a microscope one at a time until all cancerous tissue has been removed. Mole (nevus) A colored spot, mark, or small, permanent, raised growth, usually made up of melanocytes, on the human body. Morpheaform basal cell carcinoma (sclerosing basal cell carcinoma) A less-common type of basal cell skin cancer, which may look like a scar and be white or yellow in color. It usually grows quickly and can be almost an inch in length within a few months. Nevus (mole) A colored spot, mark, or small, permanent, raised growth on the human body. Nodular basal cell carcinoma The most common type of basal cell skin cancer, which looks like a smooth, round pimple and may be pearly, shiny, or gray in color. Nodular melanoma The most serious and life-threatening form of skin cancer, which may start as a bump or raised area that is dark blackish-blue or bluish-red, but may not have any color. Non-melanoma skin cancer A form of skin cancer that is less fatal than melanoma. Basal cell skin cancer and squamous cell skin cancer are both non-melanoma skin cancers. Nonsteroidal anti-inflammatory drugs (NSAIDs) Drugs that decrease fever, swelling, pain, and redness. P-Z Return to top Palliative care Care that prevents or relieves the symptoms of disease or the side effects of treatment, but does not change the outcome of a disease. Palpable A term used to describe cancer that can be felt by touch, usually present in lymph nodes, skin, or other organs of the body. Pathologist A doctor who identifies diseases by studying cells and tissues under a microscope. Photosensitivity (sun sensitivity) A skin condition that causes it to be extremely sensitive to sunlight. Pigmentation The coloring of the skin, hair, mucous membranes, and retina of the eye. Pigmented basal cell carcinoma A skin cancer that appears more often in people with dark eyes and hair. Pore A tiny opening in the skin’s surface that allows liquid or gas to pass through it. Punch biopsy Removal of a small, disk-shaped sample of tissue using a sharp, hollow surgical tool. Radiation therapy The use of high-energy rays or waves to kill cancer cells and shrink tumors. Radioactive A substance that produces energy as a stream of particles that gives off radiation. Risk factor Anything that increases a person's chance of developing a disease. Sclerosing basal cell carcinoma (morpheaform basal cell carcinoma) A less-common type of basal cell skin cancer, which may look like a scar and be white or yellow in color. It usually grows quickly and can be almost an inch in length within a few months. Screening Checking for a disease when there may be no symptoms of the disease. Sebum A thick, oily substance produced by the sebaceous glands that are located in the dermis. Sentinel lymph node The first lymph node where cancer is likely to spread from the initial tumor. Sentinel lymph node biopsy Removal and examination of the sentinel lymph node. Shave biopsy A procedure that removes skin tissue by shaving off the top layers of skin with a surgical blade. Skin An organ that makes up the external surface of the body. It consists of three main layers -- epidermis, dermis, and subcutaneous layer -- and protects the body against germs, diseases, and too much water loss. Skin biopsy Removal of a portion of skin tissue for microscopic examination. Skin cancer Cancer that forms in the tissues of the skin. Skin graft Skin that is moved from one part of the body to another to help heal the area that receives the skin graft. Skin self-examination (SSE) Checking your own skin regularly for any abnormal growths or unusual changes. Skin ulcer An area of skin that has been eroded down into the dermis layer. Solar keratosis (actinic keratosis) A precancerous skin condition that has a rough, scaly, slightly raised growth that varies in color. Squamous cells Flat cells that look like fish scales under a microscope and which cover internal and external surfaces of the body. Squamous cell carcinoma (SCC) A non-melanoma cancer that begins in squamous cells. Staging A test to help determine the stage, or amount, of cancer cells present, and if the cancer has spread to other parts of the body. Stratum corneum The outermost or top layer of the epidermis. Subcutaneous layer Fatty layer of tissue located under the dermis. Sun protection factor (SPF) A scale for rating the level of sunburn protection in sunscreen products. Sunscreen A lotion, cream, or gel that is spread over the skin to help protect it from the sun's harmful rays. Sun sensitivity (photosensitivity) A skin condition that causes it to be extremely sensitive to sunlight. Superficial basal cell carcinoma A common form of basal cell skin cancer that is a slow-spreading skin lesion with crusted surfaces and bordered with small thread-like structures. Superficial spreading melanoma A type of melanoma skin cancer that is generally flat and irregular in shape and color, with different shades of brown and black. Surface microscopy (dermoscopy, dermatoscopy, epiluminescence microscopy (ELM)) A procedure that uses a specially lighted magnifying lens to look at spots on the skin more clearly. Surgical excision A treatment that removes a skin growth or lesion, as well as a margin of skin around the lesion, with a surgical blade. Surgical lymph node biopsy A test where a lymph node or a piece of a lymph node is removed to examine under a microscope for signs of infection or disease, such as cancer. Systemic chemotherapy Treatment with anticancer drugs that travel through the blood to cells all over the body. Topical chemotherapy Treatment with anticancer drugs in a lotion or cream applied to the skin. Tumor An abnormal mass of tissue that results from too much cell division, which may be benign (non-cancerous) or malignant (cancerous). Ultraviolet A (UVA) light or radiation One of the harmful types of ultraviolet radiation (320-400 nm), responsible for the aging effects of sunlight. Ultraviolet B (UVB) light or radiation One of the harmful types of ultraviolet radiation (280-320 nm), responsible for sunburns. Ultraviolet C (UVC) light or radiation One of the harmful types of ultraviolet radiation (200-280 nm), which is absorbed by the ozone layer and does not reach the Earth. Ultraviolet (UV) radiation Invisible rays that are part of the sun’s energy and are also emitted by sun lamps and tanning beds. Xeroderma pigmentosum An inherited condition that causes sensitivity to all sources of ultraviolet radiation and reduces the skin’s ability to repair damage caused by sunlight. X-ray A type of high-energy radiation that can be used to diagnose diseases by making pictures of the inside of the body.