Some definitions to help you understand:


“Deviating from the normal or average” (Merriam-Webster)

Acral lentiginous melanoma:

“Melanoma occurring on the hands and feet (palms, soles, fingers, toes, and nail units” (National Library of Medicine)


“Of, relating to, resulting from, or exhibiting chemical changes produced by radiant energy especially in the visible and ultraviolet parts of the spectrum” (Merriam-Webster)

Actinic keratosis:

“Actinic keratosis is a rough, scaly patch or bump on the skin. […] They are caused by ultraviolet (UV) damage to the skin. Some actinic keratoses can turn into squamous cell skin cancer” (Johns Hopkins Medicine)


“Having two sides or halves that are not the same: not symmetrical” (Merriam-Webster)


“Of, relating to, or caused by autoantibodies or T cells that attack molecules, cells, or tissues of the organism producing them” (Merriam-Webster)

Basal cell carcinoma:

Basal cell carcinoma is a type of skin cancer. Basal cell carcinoma begins in the basal cells […] Most basal cell carcinomas are thought to be caused by long-term exposure to ultraviolet (UV) radiation from sunlight” (Mayo Clinic)


“The removal of tissue, cells, or fluids from someone’s body in order to check for illness” (Merriam-Webster)

BRAF Gene:

“A gene that makes a protein that is involved in sending signals in cells and in cell growth. Mutated (changed) forms of the BRAF gene and protein have been found in many types of cancer. These changes can increase the growth and spread of cancer cells” (National Cancer Institute)


“Cancer is a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body” (National Cancer Institute)


“Cancer that begins in the skin or in tissues that line or cover body organs. Examples are carcinoma of the breast, colon, liver, lung, pancreas, prostate, or stomach” (MedicineNet)


“Any one of the very small parts that together form all living things” (Britannica Dictionary)


“Chemotherapy is a drug treatment that uses powerful chemicals to kill fast-growing cells in your body. […] Many different chemotherapy drugs are available. Chemotherapy drugs can be used alone or in combination to treat a wide variety of cancers” (Mayo Clinic)

Clinical trials:

“Clinical trials are research studies that test new ways to prevent, detect, treat or manage cancer or other diseases” (Canadian Cancer Survivor Network)


“Existing at or dating from birth” (Merriam-Webster)


“Surgery in which usually diseased or abnormal tissue (as of a tumor or wart) is destroyed or removed by freezing (as by liquid nitrogen)” (Merriam-Webster)


“Uses extreme cold (liquid nitrogen or carbon dioxide) to freeze and destroy abnormal cells or tissue” (Canadian Cancer Society)

Curettage and electrodesiccation:

“A curettage [scraping] and electrodesiccation [burning], also known as a curettage and desiccation, is a skin cancer treatment used to remove basal cell and squamous cell carcinomas” (Mercy Health)


“Of, relating to, or affecting the skin” (Merriam-Webster)


“A branch of medicine dealing with the skin, its structure, functions, and diseases” (Merriam-Webster)


“The art or act of identifying a disease from its signs and symptoms” (Merriam-Webster)


“Abnormal growth or development (as of organs or cells)” (Merriam-Webster)

Dysplastic nevus:

“A dysplastic nevus is a type of mole that looks different from a common mole. […] A dysplastic nevus may be bigger than a common mole, and its color, surface, and border may be different” (National Cancer Institute)


“The drying of tissue by a high-frequency electric current applied with a needle-shaped electrode” (Merriam-Webster)


“The outer nonsensitive and nonvascular layer of the skin of a vertebrate that overlies the dermis” (Merriam-Webster).


“The act or procedure of removing by or as if by cutting out” (Merriam-Webster)

External beam radiation therapy:

“External beam radiation therapy comes from a machine that aims radiation at your cancer. It is a local treatment, which means it treats a specific part of your body.” (National Cancer Institute)


“Any of the small brownish spots in the skin due to augmented melanin production that increase in number and intensity on exposure to sunlight” (Merriam-Webster)


“A specific sequence of nucleotides in DNA or RNA that is located usually on a chromosome and that is the functional unit of inheritance controlling the transmission and expression of one or more traits” (Merriam-Webster)


“Not capable of being affected by a disease” (Britannica Dictionary)

Immune system:

“The bodily system that protects the body from foreign substances, cells, and tissues by producing the immune response” (Merriam-Webster)


“Suppression of the body’s immune system and its ability to fight infections and other diseases. Immunosuppression may be deliberately induced with drugs” (National Cancer Institute)


“Immunotherapy is a type of cancer treatment that helps your immune system fight cancer. […] Immunotherapy is a type of biological therapy. Biological therapy is a type of treatment that uses substances made from living organisms to treat cancer.” (National Cancer Institute)

In situ

“Refers to a cancerous but noninvasive tumor that has not penetrated beyond the epidermis into the dermis. […] In situ skin cancers can also become invasive if not removed in a timely way” (Skin Cancer Foundation)

Invasive Skin Cancer:

“An invasive skin cancer has penetrated beyond the epidermis into the dermis and is growing into surrounding, healthy tissue” (Skin Cancer Foundation)


“Having, producing, or marked by an uneasy sensation in the skin” (Merriam-Webster)


“An area of skin marked by overgrowth of horny tissue” (Merriam-Webster)


“An injured or diseased spot or area on or in the body” (Merriam-Webster)

Lentigo maligna melanoma:

“Lentigo maligna is an early form of melanoma in which the malignant cells are confined to the tissue of origin, the epidermis, hence it is often reported as ‘in situ’ melanoma” (DermNet NZ)

Liquid nitrogen:

“Nitrogen in a liquid state. “Nitrogen in a liquid state. Liquid nitrogen is […] used for cryopreservation, cryosurgery, and cryomedicine” (MedicineNet)


“Lymph is a pale liquid in the body that helps maintain fluid balance and removes bacteria from tissues. Today, we understand that lymph plays an important role in the body’s immune system” (Merriam-Webster)

Lymph node:

“Any of the rounded masses of lymphoid tissue that are surrounded by a capsule of connective tissue, are distributed along the lymphatic vessels, and contain numerous lymphocytes which filter the flow of lymph passing through the node” (Merriam-Webster)


“Of, relating to, or produced by lymph, lymphoid tissue, or lymphocytes” (Merriam-Webster)

Lymphatic system:

“The part of the circulatory system that is concerned especially with scavenging fluids and proteins which have escaped from cells and tissues and returning them to the blood, with the phagocytic removal of cellular debris and foreign material, and with the immune response” (Merriam-Webster)


“The quality or state of being malignant” (Merriam-Webster)


“Tending or likely to grow and spread in a rapid and uncontrolled way that can cause death” (Merriam-Webster)

Malignant melanoma:

“A tumor of high malignancy that starts in melanocytes of normal skin or moles and metastasizes rapidly and widely” (Merriam-Webster)


“Any of various black, dark brown, reddish-brown, or yellow pigments of animal or plant structures (as skin or hair)” (Merriam-Webster)


“An epidermal cell that produces melanin” (Merriam-Webster)


“A type of cancer or tumor that begins as a dark spot or area on the skin” (Merriam-Webster)


“The spread of a disease-producing agency (such as cancer cells) from the initial or primary site of disease to another part of the body” (Merriam-Webster)

Merkel Cell Carcinoma:

“Merkel cell carcinoma is a rare type of skin cancer that usually appears as a flesh-colored or bluish-red nodule, often on your face, head or neck. […] Merkel cell carcinoma most often develops in older people” (Mayo Clinic)

Mohs Surgery:

“A precise surgical technique used to treat skin cancer. During Mohs surgery, thin layers of cancer-containing skin are progressively removed and examined until only cancer-free tissue remains” (Mayo Clinic)


“A pigmented spot, mark, or small permanent protuberance on the human body” (Merriam-Webster)

Mucosal lentiginous melanoma:

“[A rare type of melanoma that] develops on the thin, moist lining of some organs or other parts of the body, such as the nasal passages, mouth and anal canal” (Canadian Cancer Society)


“Necrotic tissue is a medical condition in which there are dead cells in your body organ. The death of the cells happens due to lack of oxygen and interrupted blood supply. It causes the cells to be acidic, releasing enzymes that break the cells” (Medanta)


The plural form of nevus [below]


“A congenital or acquired usually highly pigmented area on the skin that is either flat or raised” (Merriam-Webster)


“A discrete mass of one kind of tissue enclosed in tissue of a different kind” (Merriam-Webster)

Nodular melanoma:

“The second most common type of skin melanoma. […] It grows and spreads more quickly than other types of melanoma. It is most commonly found on the face, chest, or back” (Canadian Cancer Society)

Non-melanoma skin cancers:

“Non-melanoma skin cancer starts in the cells of the skin. A cancerous (malignant) growth is a group of cancer cells that can grow into and destroy nearby tissue. It can also spread (metastasize) to other parts of the body, but this is rare with non-melanoma skin cancer” (Canadian Cancer Society)

Ocular Melanoma:

Ocular melanoma is a rare cancer that develops in the melanin, or cells which produce pigment, in the eye. The term ocular melanoma inclusively refers to all melanomas in the eye, including those occurring in the conjunctiva (American Academy of Ophthalmology). The terms ocular and uveal melanoma are often used interchangeably.


“The study and treatment of cancer and tumors” (Merriam-Webster)

Photodynamic Therapy:

“Photodynamic therapy uses a drug that is activated by light, called a photosensitizer or photosensitizing agent, to kill cancer cells” (National Cancer Institute)


“A coloring matter in animals and plants especially in a cell or tissue” (Merriam-Webster)


“Likely to become cancerous” (Merriam-Webster)


“One that precedes and indicates the approach of another” (Merriam-Webster)

Punch biopsy:

“A biopsy in which a small, round sample of tissue (such as skin) is obtained by using an instrument with a circular blade” (Merriam-Webster)


“The treatment of disease with radiation (as X-rays)” (Merriam-Webster)


“Occurring repeatedlyhappening or appearing multiple times” (Merriam-Webster)


“A small thin dry lamina shed (as in many skin diseases) from the skin” (Merriam-Webster)

Skin Graft

“A skin graft is a patch of skin that is removed by surgery from one area of the body and transplanted, or attached, to another area” (Mount Sinai)


“A localized sore spot on the body; especially :  one (as an ulcer) with the tissues ruptured or abraded and usually with infection” (Merriam-Webster)

SPF (sun protection factor):

“SPF is a measure of how much solar energy (UV radiation) is required to produce sunburn on protected skin (i.e., in the presence of sunscreen) relative to the amount of solar energy required to produce sunburn on unprotected skin. As the SPF value increases, sunburn protection increases.” (US Food and Drug Administration)

Squamous cell carcinoma (SCC):

“Squamous cell carcinoma of the skin is a common form of skin cancer that develops in the squamous cells that make up the middle and outer layers of the skin” (Mayo Clinic)


“Staging is a way of describing or classifying a cancer based on the extent of cancer in the body” (Canadian Cancer Society)


“Sunburn is inflamed, painful skin that feels hot to the touch. It often appears within a few hours of being in the sun too long. […] Sunburn is caused by too much exposure to ultraviolet (UV) light. UV light may be from the sun or artificial sources, such as sunlamps and tanning beds” (Mayo Clinic)


“A substance that helps protect the skin from the sun’s harmful rays. Sunscreens reflect, absorb, and scatter both ultraviolet A and B radiation to provide protection against both types of radiation” (National Cancer Institute)


“Lying on, not penetrating below, or affecting only the surface” (Merriam-Webster)

Superficial spreading melanoma:

“Superficial spreading melanoma is the most common type of melanoma skin cancer. It makes up about 70% of all melanoma skin cancers. Superficial spreading melanoma tends to grow outward (called radial growth) and spread across the surface of the skin. But it can also start to grow down into the skin (called vertical growth)” (Canadian Cancer Society)


“Correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis” (Merriam-Webster)

Targeted Therapy:

“A treatment that focuses on attacking certain traits of skin cancer cells, such as gene changes” (Everyday Health)

TIL Therapy

“A type of treatment in which tumour-infiltrating lymphocytes (a type of immune cell that can recognize and kill cancer cells) are removed from a patient’s tumour and grown in large numbers in a laboratory. These lymphocytes are then given back to the patient by infusion to help the immune system kill the cancer cells” (National Cancer Institute)


“Therapeutic medical treatment of impairment, injury, disease, or disorder” (Merriam-Webster)


“Designed for or involving local application and action (as on the body)” (Merriam-Webster)


“To perform a medical operation in which an organ or other part that has been removed from the body of one person is put it into the body of another person” (Merriam-Webster)


“An abnormal benign or malignant new growth of tissue that possesses no physiological function and arises from uncontrolled usually rapid cellular proliferation” (Merriam-Webster)


“Situated beyond the visible spectrum at its violet end—used of radiation having a wavelength shorter than wavelengths of visible light and longer than those of X-rays” (Merriam-Webster)


“Radiation that is in the region of the ultraviolet spectrum which extends from about 320 to 400 nm in wavelength and that causes tanning and contributes to aging of the skin” (Merriam-Webster)


“Radiation that is in the region of the ultraviolet spectrum which extends from about 280 to 320 nm in wavelength and that is primarily responsible for sunburn, aging of the skin, and the development of skin cancer” (Merriam-Webster)

Uveal Melanoma:

Uveal melanoma is a rare cancer which initially develops in the melanin, or the cells which make the dark-coloured pigment, specifically in the uveal tract (or uvea) of the eye. The uveal tract is the middle layer of the wall of the eye and includes the iris, the choroid, and the ciliary body. Uveal melanoma in the choroid or ciliary body are usually more likely to metastasize and are often larger in size, while uveal melanoma in the iris are usually small tumours that are less likely to spread (National Cancer Institute). The terms uveal and ocular melanoma are often used interchangeably.

UV Index:

The UVI is a measure of the level of UV radiation, [with] the values of the index rang[ing] from zero upward – the higher the UVI, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur” (World Health Organization)


“A small, hard lump on the skin caused by a virus” (Merriam-Webster)


“A disease of the skin characterized by dryness and roughness and a fine scaly desquamation” (Merriam-Webster)

Xeroderma pigmentosum:

“A genetic condition inherited chiefly as a recessive autosomal trait that is caused by a defect in mechanisms that repair DNA mutations (as those caused by ultraviolet light) and is characterized by the development of pigment abnormalities and multiple skin cancers in body areas exposed to the sun” (Merriam-Webster)

NOTE: The information on the Save Your Skin website is not intended to replace the medical advice of a doctor or healthcare provider. While we make every effort to ensure that the information on our site is as current as possible, please note that information and statistics are subject to change as new research and studies are published. 


Making awareness and education available is crucial. Since 2006, the Foundation has worked to raise awareness of melanoma and non-melanoma skin cancers focusing on education, prevention and the need for improved patient care.