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Education Institute


Common Melanoma Terms

Following is a list of terms commonly used by oncologists, dermatologists and pathologists, and that you may see on your patient record or pathology report. Still have questions? Email the MRF nurse or visit the patient forum to find answers.


Acral Lentiginous

A kind of lentiginous skin melanoma It is also known as subungual melanoma. Acral lentiginous melanoma is observed on the palms, soles and under the nail. It occurs on non hair-bearing surfaces of the body which may or may not be exposed to sunlight. It is also found on mucous membranes. Unlike other forms of melanoma, acral lentiginous melanoma does not appear to be linked to sun exposure.

Adjuvant Therapy

Adjuvant therapy in melanoma is a treatment or treatments that are given after primary treatment in order to lower the risk of recurrence (that the cancer may return). In the past, adjuvant therapies were primarily chemotherapy and radiation, but newer, recently approved systemic (traveling through the bloodstream) and targeted adjuvant therapies mean that medicines can target cells or enhance the immune system anywhere in the body.


Asymmetry of a skin spot; one half does not match the other.


Basal Cell Carcinoma

A type of common, non-melanoma skin cancer that arises from the basal cells – small round cells found in the lower part of the epidermis, the outer layer of the skin.


Not malignant; not recurrent; favorable for recovery.


A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition. Also called molecular marker and signature molecule.


The removal of cells or tissues for examination under a microscope.

Blood Vessel/Lymphatic Invasion

Blood vessel invasion, aka angioinvasion, as well as lymphatic invasion are described as being present or absent. If present it means that the melanoma has invaded the blood or lymph system respectively.

Bone Scan

A bone scan is used to determine if the cancer has spread to the bones, but is rarely used in melanoma.


The BRAF (pronounced “B-raf”) gene helps control cell growth. In about half of skin melanoma cases, the BRAF gene is mutated. This mutation can cause the cell to grow out of control, which can lead to cancer. Certain targeted therapy drugs exist that try to target the BRAF mutation to stop the melanoma from spreading.

Breslow Thickness

The depth a melanoma lesion extends below the skin surface measured in millimeters



The individual unit that makes up all of the tissues of the body.

Cellular Description (the type of melanoma)

  • Superficial Spreading Melanoma
  • Nodular Melanoma
  • Acral Lentiginous Lentigo Melanoma
  • Mucosal melanoma


Treatment of cancer with anticancer drugs.

Chest X-Ray

A Chest X-Ray is often performed to determine if the melanoma has metastasized to the lungs.

Clark’s Level Depth

A measurement of how deep the melanoma lesion extends below the skin surface based on involved skin layer (the larger the level number the deeper into the tissue it extends). Depending upon where the melanoma is located on the body, the millimeters of depth for each Clark level can vary widely, so one person’s Clark’s III may be 1 mm, while another person’s is 2 mm.

  • Clark’s Level I—lesion involves the dermis
  • Clark’s Level II—lesion involves the papillary dermis
  • Clark’s Level III—lesion invades and fills the papillary dermis
  • Clark’s Level IV—lesion invades reticular dermis
  • Clark’s Level V—lesion invades sub-cutaneous tissue

Clinical Trial

A type of research study that tests how well new medical treatments or other interventions work in people. May also be called a clinical study.

Computed Tomography (CT) Scan

The CT scan is more detailed than the x-ray and provides cross-sectional images of the body, specifically the soft tissues. The CT scanner takes several pictures as it rotates around the patient and then combines the pictures to provide a detailed image. Sometimes a contrast dye is used to better identify abnormal areas of the body.


Pertaining to the skin.


A class of substances that are produced by cells of the immune system and can affect the immune response. Cytokines can also be produced in the lab by recombinant DNA technology and given to people to affect immune responses.



The medical specialty concerned with the diagnosis and treatment of skin diseases.


The lower or inner layer of the two main layers of tissue that make up the skin.


The determination of the nature of a case of a disease or the distinguishing of one disease from another.


Dormancy of the tumor or cancer cells occurs when cancer cells are present but the tumor does not grow. The idea of tumor dormancy originated from clinical findings that recurrence of cancer may occur several years or even several decades after surgical resection of the primary tumor. 

Dysplastic nevi

Atypical moles; moles whose appearance is different from that of common moles. Dysplastic nevi are generally larger than ordinary moles (over 5 mm in diameter) and have irregular and indistinct borders. Their color frequently is not uniform and ranges from pink to dark brown; they are flat or have a flat part.



The upper or outer layer of the two main layers of tissue that make up the skin.

Excisional Biopsy

Technique in which a lesion is removed from the skin by cutting out the affected area as well as a portion of normal skin surrounding the lesion. This technique is also used to remove larger lesions.


Fine Needle Aspirate (FNA)

Technique in which a needle is inserted into the tissue or tumor to aspirate (take out) fluid and cells. This tissue/fluid is smeared onto a slide and is then looked at under a microscope. FNA can be performed in the office or under radiology guidance.


Gene Therapy

Treatment that alters a gene.


Immune Checkpoint Inhibitor

A type of drug that blocks proteins (called checkpoints) that are made by some types of immune system cells, such as T cells, and some cancer cells. These checkpoints help keep immune responses from being too strong and sometimes can keep T cells from killing cancer cells. When these checkpoints are blocked, T cells can kill cancer cells better. In melanoma, some examples of checkpoint proteins found on T cells or cancer cells include PD-1/PD-L1 and CTLA-4. 


Passive immunization of an individual by administration of preformed antibodies (serum or gamma globulin) actively produced in another individual; by extension, the term has come to include the use of immunopotentiators, replacement of immunocompetent lymphoid tissue (e.g., bone marrow or thymus), etc

In Situ

In its normal place; confined to the site of origin.

In-Transit Metastasis

The melanoma spreads through the lymph system and begins to grow more than 2 centimeters away from the primary tumor but before it reaches the nearest lymph node. These metastases may become palpable or visible at or just below the skin.

Incisional Biopsy

Technique in which a lesion is removed from the skin by cutting out the affected area. This technique is often used to remove larger lesions.


Having the quality of invasiveness. Involving puncture of the skin or insertion of an instrument or foreign material into the body; said of diagnostic techniques


Lentigo Maligna Melanoma

A melanoma that has evolved from a lentigo maligna. They are usually found on chronically sun damaged skin such as the face and the forearms of the elderly. This type of melanoma starts as a flat, irregularly bordered patch on the skin, usually darkening over the years, making it difficult to notice the changes.

Leptomeningeal Metastasis

When melanoma cells spread from the original (primary) tumor to the meninges (thin layers of tissue that cover and protect the brain and spinal cord). It can happen in many types of cancer, but is the most common in melanoma, breast, lung, and gastrointestinal cancer. The cancer may cause the meninges to be inflamed. 


Any pathological or traumatic discontinuity of tissue or loss of function of a part.

Lymph Node

Any of the small, oval or round bodies, located along the lymphatic vessels, that supply lymphocytes to the bloodstream and remove bacteria and foreign particles from the lymph. Also called lymph gland, lymphoglandula, lymphonodus.

Lymphatic System

The interconnected system of spaces and vessels between body tissues and organs by which lymph circulates throughout the body.

Lymphedema Involves blockage of the lymph vessels, with a resulting accumulation of lymphatic fluid in the interstitial tissues of the body. The lymphatic system consists of lymph vessels and lymph nodes throughout the body. The lymph vessels collect lymphatic fluid, which consists of protein, water, fats, and wastes from cells. The lymph vessels transport the fluid to the lymph nodes, where waste materials and foreign materials are filtered out from the fluid. The fluid is then returned to the blood. When the vessels are damaged or missing, the lymph fluid cannot move freely throughout the system but accumulates. This accumulation of fluid results in abnormal swelling of the arm(s) or leg(s), and occasionally swelling in other parts of the body.


Magnetic Resonance Imaging (MRI)

MRI’s provide detailed pictures of the soft tissue of the body using radio waves and strong magnets. MRI scans are very helpful in looking at the brain and the spinal cord.


Tending to become worse and end in death. Having the properties of anaplasia, invasiveness, and metastasis; said of tumors.


The edge or border of the tissue removed in cancer surgery. The margin is “negative” or clean when the pathologist finds no cancer cells at the edge of the tissue, suggesting that all of the cancer has been removed. The margin is “positive” or involved when the pathologist finds cancer cells at edge of the tissue, suggesting that all of the cancer has not been removed.

Medical Indication

A sign, symptom, or medical condition that leads to the recommendation of a treatment, test, or procedure.

Medical Oncologist

A doctor who specializes in diagnosing and treating cancer using chemotherapy, hormonal therapy, biological therapy, and targeted therapy. A medical oncologist often is the main health care provider for someone who has cancer. A medical oncologist also gives supportive care and may coordinate treatment given by other specialists.


The substance made by melanocytes that gives color to skin and eyes and that absorbs UV rays


Cells in the skin and eyes that produce the pigment called melanin and that transfers it to surrounding skin cells.


A tumor arising from melanocytes within the skin or other organs; melanoma is often referred to as malignant melanoma.


The term used to describe a secondary cancer, or one that has spread from one area of the body to another.


The microbiome is the collection of the billions of bacteria, fungi and viruses found in our bodies. The majority of these reside in our guts, making up the gut microbiome. Primarily, they aid in digestion, but recently, the gut microbiome has been thought to have an influence on a melanoma patient’s response to immunotherapy treatments. Researchers are working to learn more about the gut microbiome, and also working to determine if the gut microbiome can be changed to help more patients respond to treatments.

Mitotic Rate

This term describes the frequency of division within the melanoma. Higher mitotic rates are associated with more rapidly dividing cells, and therefore larger lesions with greater potential for metastasis.


A benign growth on the skin (usually tan, brown, or flesh-colored) that contains a cluster of melanocytes and surrounding supportive tissue.


Refers to having a disease or a symptom of disease, or to the amount of disease within a population.


A term also used for death rate or the number of deaths in a certain group of people in a certain period of time.

Mucosal Melanoma

Develops in the mucous membrane that lines the nose, mouth, esophagus, anus, urinary tract and vagina. Mucosal melanomas are especially difficult to detect because they can easily be mistaken for other, far more common conditions.



A benign growth on the skin, such as a mole.

Neoadjuvant Therapy

Defined as a systemic therapy given before primary treatment. In melanoma, this often refers to treatment given before surgery in an effort to shrink the tumor.


A new growth of tissue in which cell multiplication is uncontrolled and progressive.

Nodular Melanoma

Is the most aggressive form of melanoma. It grows in vertical direction from the outset and grows very fast (months). Nodular melanoma has no known precursor. It is a small black, or if amelanotic, pink nodule that simply enlarges. The lesions tend to bleed.



The sum of knowledge regarding tumors; the study of tumors.

Oncology Nurse

A nurse who specializes in treating and caring for people who have cancer.

Oncology Social Worker, Counselor, or Patient Navigator

A person with a master’s degree in social work who works with cancer patients. The oncology social worker/counselor provides counseling and assistance. Patient Navigators are health care professionals whose primary focus is to assist cancer patients, caregivers, and families in “bridging the gaps” within the health care system and decreasing barriers to care by utilizing resources.


Palliative Care

Care that prevents or relieves the symptoms of cancer or other diseases. Palliative care does not alter the course of the disease but can improve the quality of life.


A specialist in pathology; one who interprets and diagnoses the changes caused by disease in tissues and body fluids.


Colored by deposit of pigment.

Plastic Surgeon

A surgeon who specializes in reducing scarring or disfigurement that may occur as a result of accidents, birth defects, or treatment for diseases

Positron Emission Tomography (PET) Scan

For a PET scan, the patient is injected with glucose that contains a radioactive atom. The cancer cells in the body will absorb the radioactive sugar. The camera will then capture the areas of radioactivity in the body, helping the doctor determine how much the melanoma has spread.

Precision Medicine

Precision medicine is also called personalized medicine. It is a tailored approach to predict diagnostic, treatment and prevention strategies for each patient, rather than a large group of patients. Drugs targeting the BRAF mutation in certain melanoma patients is one example of precision medicine.  

Primary Tumor

The original tumor


A forecast of the probable course and outcome of a disorder

Punch Biopsy

Technique in which a lesion is removed from the skin using a cookie cutter type device. This is used to remove small lesions or to sample a portion of a larger lesion.


Radial Growth Phase (RGP)

The melanoma lesion is described as either having RGP present or absent. If present, RGP indicates that the melanoma is growing horizontally or radially, within a single plane of skin layer


Treatment of disease by means of ionizing radiation; tissue may be exposed to a beam of radiation, or a radioactive element may be contained in devices (e.g., needles or wire) and inserted directly into the tissues, or it may be introduced into a natural body cavity


The return of symptoms after a remission


Regression is described as either being present or absent. If it is present the extent of regression is identified. Regression describes an area within the melanoma where there is absence of melanocytic growth. When regression is present the total size of the melanoma is hard to characterize.


Surgery to remove tissue or part or all of an organ.


The failure of cancer cells, viruses, or bacteria to respond to a drug used to kill or weaken them. The cells, viruses, or bacteria may be resistant to the drug at the beginning of treatment, or may become resistant after being exposed to the drug.

Risk Factor

Anything that increases a person’s chance of developing a disease.



Satellite lesions are nodules of tumor/melanoma located more than 0.05 mm from the primary lesion. Satellites are described as being present or absent.

Sentinel Lymph Node

The first lymph node to which cancer is likely to spread from the primary tumor.

Sentinel Lymph Node Biopsy

Removal and examination of the first lymph node(s) to which cancer cells are likely to spread from a primary tumor.

Shave Biopsy

Technique in which a portion of a lesion is cut off the surface of the skin using a scalpel in most cases. This is often performed by a dermatologist in the office.

Squamous Cell Carcinoma of the Skin

A common, non-melanoma skin cancer that begins in squamous cells, which are thin, flat cells that look like fish scales.

Superficial Spreading Melanoma (SSM)

SSM is usually characterized as the most common form of cutaneous melanoma in Caucasians. The average age at diagnosis is in the fifth decade, and it tends to occur on sun-exposed skin, especially on the backs of males and lower limbs of females.


Surgeon is a person who performs surgery

Surgical Oncologist

A doctor who performs biopsies and other surgical procedures in cancer patients

Symptom Management

Care given to relieve the problems associated with a disease or its treatment.


Affecting the whole body; not localized.


Targeted Therapy

A form of treatment in which drugs (or other substances) are developed with the goal of destroying cancer cells while leaving normal cells intact. These drugs are designed to interfere with the specific molecules that are driving the growth and spread of the tumor.

Tumor Swelling

One of the cardinal signs of inflammation; morbid enlargement.

Tumor-Infiltrating Lymphocytes (TILs)

TILs describes the patient’s immune response to the melanoma. When the pathologist examines the melanoma under the microscope he/she looks for the number of lymphocytes, or white blood cells, within the lesion. This is usually described as brisk, non-brisk, or absent, although occasionally it can be described as mild or moderate. The presence of these cells may be a sign of an immune response.



Ulceration is the sloughing of dead tissue. This can sometimes occur in the center of a melanoma lesion. The presence of ulceration may alter the stage classification of a melanoma. Ulceration is thought to reflect rapid tumor growth, leading to the death of cells in the center of the melanoma.


Ultraviolet radiation with wavelengths between 320 and 400 nm, comprising over 99 percent of that reaching the surface of the earth. It enhances the harmful effects of UVB, is responsible for some photosensitivity reactions, and is used therapeutically in the treatment of various skin disorders.


Ultraviolet radiation with wavelengths between 290 and 320 nm, comprising 1 percent of that reaching the surface of the earth. It causes sunburn and a number of damaging photochemical changes within cells, including damage to DNA leading to premature aging of the skin, premalignant and malignant changes, and various photosensitivity reactions; it is also used therapeutically in the treatment of skin disorders.



A substance or group of substances meant to cause the immune system to respond to a tumor or to microorganisms, such as bacteria or viruses. A cancer vaccine can help the body recognize and destroy cancer cells or microorganisms.

Vertical Growth Phase (VGP)

The melanoma is described as either having VGP present or absent. If present it is an indication that the melanoma is growing vertically or deeper into the tissues.