Melanoma in AdultSee also in: Anogenital,Hair and Scalp,Oral Mucosal Lesion
Alerts and Notices
SynopsisMelanoma is an aggressive malignancy of pigment-producing cells known as melanocytes. Melanoma may arise at sites of melanocytes including on the skin, on mucous membranes, around the nail apparatus (see nail melanoma), and in the eye. There are 4 main subtypes of melanoma: superficial spreading melanoma (the most common type), nodular melanoma, lentigo maligna melanoma, and acral lentiginous melanoma (the least common type).
The etiology of melanoma is incompletely understood, although ultraviolet radiation is believed to play a role in some melanomas and knowledge of the melanoma genome continues to advance. Melanoma susceptibility genes have been associated with melanoma tumor syndromes and some other familial tumor syndromes; these include mutations in CDKN2A/CDK4 (familial atypical multiple mole melanoma syndrome [FAMMM syndrome]), BAP1 (BAP1 cancer syndrome), MITF (MITF tumor syndrome), TERT/Shelterin complex, and PTEN). Melanoma has been shown to have one of the highest mutation rates of any cancer type, reflective of its clinical and pathologic diversity and resistance to treatment in advanced stages.
Risk factors for melanoma include a family history or prior personal history of melanoma, a history of severe or blistering sunburns, a changing mole, a giant congenital nevus (greater than 20 cm), older age, lighter skin phototype, and multiple atypical nevi. In a case control study of over 1000 patients, 3 or more iris pigmented lesions conferred an increased risk for cutaneous melanoma. Men are more prone to developing melanoma on the head, neck, and trunk, whereas women tend to develop melanoma on the arms and legs. Parkinson disease is associated with an increased risk of melanoma. The median age at diagnosis is in the 60s. The number of new cases of melanoma in the United States has been steadily rising since 1975, with an estimated 76 380 new cases of melanoma in the United States in 2016. The lifetime risk of being diagnosed with melanoma in the United States is estimated to be 2.1%.
The primary prognostic feature of melanoma is the depth of invasion, which is measured histologically in millimeters and referred to as the Breslow thickness. Early diagnosis and treatment of thin melanomas can lead to a generally favorable prognosis (97% and 93% for 5- and 10-year survival for a T1aN0M0 melanoma; see staging below), while with advanced forms the prognostic outlook is less favorable. Mortality rates are higher among men than among women. Melanoma can metastasize to any organ of the body. The most frequent sites are skin / subcutaneous, lymph nodes, lungs, liver, and brain.
Related topic: amelanotic melanoma
C43.9 – Malignant melanoma of skin, unspecified
372244006 – Malignant melanoma
Differential Diagnosis & Pitfalls
- Atypical nevus
- Seborrheic keratosis – presence of pseudo-horn cysts is typical
- Pigmented basal cell carcinoma – pearly quality
- Squamous cell carcinoma in situ (Bowen disease, pagetoid or pigmented)
- Spitz nevus
- Compound nevus
- Congenital nevus
- Blue nevus
- Lentigo simplex
- Solar lentigo
- Lobular capillary hemangioma (pyogenic granuloma) – friable, glistening surface
- Hemangioma – cherry, thrombosed
- Dermatofibroma – firm, tan or brown papule with positive dimple sign
- Halo nevus – tan or brown papule with surrounding depigmented patch
- Metastatic carcinoma
- Paget disease
- Tinea nigra
- Subungual hematoma
- Pigmented actinic keratosis
- Talon noir (black heel)
- Longitudinal melanonychia (a pigmented line along the length of a nail plate) may be a benign finding or a sign of a nail matrix melanoma. Hutchinson's sign – the presence of pigment in the proximal nail fold in a patient with longitudinal melanonychia – should prompt consideration of a nail matrix melanoma.
- Recurrent melanocytic nevus – History of the initial biopsy is often critical for the dermatologist and/or pathologist. Recurrent nevi characteristically occur on the trunk within 6 months of the original biopsy in women aged 20-30 years. While many different clinical morphologies may be seen, it often manifests as a scar with variegated hyper- or hypopigmentation, linear streaking, and halo, stippled, and/or diffuse pigmentation patterns. While most cases do not pose a diagnostic challenge on histopathology, some specimens, especially partial biopsies, may look indistinguishable from melanoma on histopathologic grounds alone.
Drug Reaction DataBelow is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
Patient Information for Melanoma in Adult
OverviewSkin cancer is the most common cancer in the United States, and it is the sixth most common cause of cancer death in the United States. Melanoma is the least common of the skin cancers (the other types are squamous cell carcinoma and basal cell carcinoma), but it is the most serious. It can be life threatening if it spreads (metastasizes) to other parts of the body. The frequency of diagnosis of melanoma has been increasing in recent years, faster than any other cancer.
Melanoma starts in the color-producing cells of the skin and may develop in an existing mole or may occur as a new mole. Early diagnosis and treatment can lead to a complete cure, while advanced forms are likely to have a poor outcome. Advanced melanoma can spread to lymph nodes as well as other areas in the body, typically the lungs, liver, and brain.
Who’s At RiskYou have an increased risk of developing melanoma if you have:
- A family history of melanoma - Having someone in your family with melanoma increases your risk tenfold.
- Fair skin, light eyes, and a tendency to freckle - The risk of getting melanoma is 1 in 50 for whites, 1 in 200 for Hispanics, and 1 in 1,000 for people of African descent.
- A large number of moles, especially unusual appearing moles.
- History of frequent sun exposure, especially in childhood.
- History of sunburns.
- Decreased immune system, such as transplant patients and patients with HIV/AIDS.
Sunlamps and tanning beds may increase your risk of melanoma, especially if they cause sunburn.
Signs & SymptomsMelanoma usually occurs on areas of the skin that are exposed to the sun, but it may be found anywhere on the body, including the eye, mouth, and genital area.
- Men are most likely to develop melanoma on the head, neck, and trunk.
- Women are most likely to develop melanoma on the legs and arms.
- A - Asymmetry: One half of the mole does not look like the other half.
- B - Border: The outline of the mole is irregular.
- C - Color: More than one color can be seen, such as brown, black, red, blue, and white.
- D - Diameter: A mole larger than 6 mm (1/4 inch), which is roughly the size of a pencil eraser.
- E - Evolving: Changes in the mole over time.
Self-Care GuidelinesProtective measures, such as avoiding skin exposure to sunlight during peak sun hours (10 AM to 3 PM), wearing protective clothing, and applying high-SPF sunscreen, are essential for reducing exposure to harmful ultraviolet (UV) light. These protective measures are especially important in children because 80% of our lifetime exposure to UV light occurs before age 18.
Once a month, you should perform a self-exam to look for signs of skin cancer. It is best to perform the exam in a well-lit area after a shower or bath. Use a full-length mirror with the added assistance of a hand mirror when necessary. Using a hair dryer can help you examine any areas of skin covered by hair, such as your scalp.
- In front of a full-length mirror, inspect the front of your body, making sure to look at the front of your neck, chest (including under breasts), legs, and genitals.
- With your arms raised, inspect both sides of your body, making sure to examine your underarms.
- With your elbows bent, examine the front and back of your arms as well as your elbows, hands, fingers, area between your fingers, and fingernails.
- Inspect the tops and bottoms of your feet, the area between your toes, and toenails.
- With your back to the mirror and holding a hand mirror, inspect the back of your body, including the back of your neck, shoulders, legs, and buttocks.
- Using a hand mirror, examine your scalp and face.
When to Seek Medical CareUse the ABCDE checklist described above to help you decide which moles are concerning for melanoma. If you have a mole that you think fits one or more of these descriptions, call your doctor so he or she can thoroughly examine your skin.
TreatmentsIf your doctor thinks that your mole is suspicious for melanoma, you will need a skin biopsy, usually performed by a dermatologist. The goal of the biopsy, also called an excision, is to remove the entire mole and to get a diagnosis.
Prognosis and treatment depend on how deep the tumor has grown into the skin. If you have a melanoma that is very thin (less than 1 mm) and has been completely removed with the excision, this may be all the treatment you need.
For thicker melanomas, your doctor will probably recommend a biopsy of your lymph nodes to determine if they contain melanoma cells. This is called a sentinel node biopsy. If these lymph nodes do have melanoma cells, you may need to have other lymph nodes surgically removed.
If you have lymph nodes that contain melanoma, your doctor will also need to determine if the melanoma has spread to other parts of your body. You may have to have a chest X-ray, a CT scan, an MRI, and/or other tests to determine this.
Treatment for melanoma that has spread to the lymph nodes or other parts of the body may include chemotherapy. For patients with melanoma that has metastasized, immunotherapy is another treatment that can help the body's own immune system to destroy cancer cells. Types of immunotherapy include vaccines, cytokines (proteins that boost the immune system), and interferon-alpha.
If you have previously been diagnosed and treated for melanoma, you are at increased risk of developing another melanoma, especially in the first 3 years after diagnosis. Therefore, it is essential that you regularly follow up with your doctor to have a thorough skin examination.
American Cancer Society. Detailed Guide: Skin Cancer - Melanoma. http://www.cancer.org/docroot/CRI/CRI_2_3x.asp?rnav=cridg&dt=39. Accessed on January 31, 2009.
Bolognia, Jean L., ed. Dermatology, pp.1789-1815. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed, pp.917. New York: McGraw-Hill, 2003.
Ragel EL, Bridgeford EP, Ollila DW. Cutaneous melanoma: update on prevention, screening, diagnosis, and treatment. Am Fam Physician. 2005;72(2):269-276. PMID: 16050450.
Melanoma in AdultSee also in: Anogenital,Hair and Scalp,Oral Mucosal Lesion