Recognizing Melanoma: What It Is, What It Isn't - Medpage Today

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Key Points

"Medical Journeys" is a set of clinical resources reviewed by physicians, meant for the medical team as well as the patients they serve. Each episode of this 12-part journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.

Melanomas can hide in plain sight, surrounded by moles, freckles, birth marks, and other skin imperfections that distract attention from the cancerous threat.

ABCDE

Fortunately, following the trail of a handful of common melanoma characteristics can establish the course to a correct diagnosis. Originally developed for patients, the American Academy of Dermatology ABCDE rules of melanoma recognition also readily apply to the initial clinical examination of suspicious lesions:

• A - Asymmetry: one half of the melanoma does not match the other

• B - Border irregularity: Ragged edges, notched or blurred appearance

• C - Color: Not uniform in color, different shades of brown or tan, specks of red, white, or blue

• D - Diameter: Size that is usually, but not always, larger than 6 mm in diameter (about ¼ in.)

• E - Evolving: Visually different from other moles or skin lesions; appears to be changing in size, shape, or color

Other characteristics that can guide a diagnosis toward or away from melanoma include anatomic location of a lesion, personal and medical history, skin type, and lifestyle factors. A comprehensive evaluation of a patient's skin status and a suspicious lesion should take into account all of the factors.

Types of Skin Lesions: Benign and Otherwise

Knowing what is not melanoma plays a key role in recognizing what is.

Common Moles

A mole (or nevus) is essentially a cluster of pigmented cells (melanocytes). In general, moles have a uniform appearance. Most moles (or nevi, plural) are brown, round, flat or slightly raised, and do not change in size or appearance from month to month. Typically, they are no bigger than the eraser on a pencil and often are smaller.

Generalities aside, it is important to remain cognizant of variations and outliers. The color of a mole can range across tan, black, red, pink, blue, and skin-toned -- or even be colorless. Some moles have hair. Although the size or appearance may not change from month to month, some moles change slowly over time and might even disappear.

Moles can arise anywhere on the body, but most often appear above the waist on areas exposed to sunlight. Most adults have 10 to 40 moles, and people can continue to develop moles until about age 40. In older people, moles may fade. Most people with dark skin and/or hair have darker moles.

Rarely, a common mole can evolve into melanoma. Signs that should be viewed with some suspicion include changes in size, color, shape, texture, or height, or a mole that becomes dry, scaly, or itchy or starts to bleed or ooze. People who have many moles -- more than 50, and especially more than 100 -- have an increased risk of developing melanoma.

Atypical Mole or Dysplastic Nevus

As the name suggests, an atypical mole differs from the common form in one or more key characteristics, such as size (larger), color, and shape.

Despite the different appearance, atypical moles usually remain stable over time and do not give rise to melanoma. One exception is the person who has five or more dysplastic nevi. The risk of melanoma is greater as compared with a person who has no dysplastic nevi. The likelihood of melanoma increases as the number of dysplastic nevi increases beyond five.

Congenital Moles

Some people are born with one or more moles, known as congenital moles. They vary in size from small to quite large and have a range of possible colors. A congenital mole increases the likelihood of melanoma, particularly for a person with multiple congenital moles.

The lesions can appear anywhere on the body but are most commonly found on the trunk and extremities.

Spitz Nevus

A Spitz nevus is a benign skin growth, but the presence of the lesion is associated with an increased risk of developing melanoma. The growth shares a number of characteristics with melanoma, and at one time was considered a form of skin cancer.

The classic Spitz nevus appearance is pink, raised, and dome-shaped, but the lesion can have a mix of colors, including red, black, and brown.

Spitz nevi occur most often on the face, neck, or legs, but can also occur on the arms, shoulders, or trunk.

A Spitz nevus may bleed, and in some cases may develop an opening that oozes. The growths usually appear during the first 20 years of life. They tend to grow fairly quickly before stabilizing. In older age, a Spitz nevus may regress.

Actinic Keratoses

These cancer-precursor lesions tend to arise on skin areas that have been most damaged by exposure to sunlight: face, ears, balding scalp, hands, neck, or lips. An actinic keratosis (AK) on the lip also is known as actinic cheilitis. Because of their precancerous status, all AKs should be evaluated by a dermatologist or skin cancer specialist.

AKs appear most often on people who are age 40 or older. Not uncommonly, an AK initially has a subtle appearance, such as a patch of rough or scaly skin that is a shade of pink. In contrast to benign moles or nevi, an AK may feel painful when rubbed or scratched.

In some cases, an AK appears as a brown patch and might be mistaken for normal skin aging. However, the patch will feel rough or scaly. Actinic cheilitis may resemble a whitish, dry area on the lip and may crack easily. If neglected, AK can evolve into a horn-like growth on the skin, which is associated with a heightened risk of skin cancer and should be evaluated right away by a skin specialist.

Seborrheic Keratosis

Benign growths associated with aging, seborrheic keratoses appear as brown, black, or tan growths that are slightly raised and have a waxy or scaly texture. The most common sites are the face, neck, chest, and back. They vary in size from small to more than an inch in diameter. Itchiness is a fairly common characteristic.

A patient might consider having a seborrheic keratosis surgically removed if the lesion becomes irritated or bleeds.

Considering Skin Lesions in Context

The vast majority of skin lesions are not melanoma. However, the aggressive and potentially fatal nature of melanoma makes awareness, vigilance, and early recognition imperative. To counter a risk of overdiagnosis and overtreatment, keep in mind the distinguishing features of melanoma and consider them in light of patient-specific factors and family history.

The risk of melanoma is increased in patients who:

• Have fair skin, red or blond hair, and blue eyes, and especially the combination

• Have a history of chronic and intense exposure to sunlight, including use of tanning salons or personal tanning equipment

• Are more likely to sunburn rather than tan

• Have a history of sunburn at an early age, especially multiple episodes of sunburn

• Have a personal or family history of skin cancer

• Have 50 or more moles, whether typical or atypical

Skin Biopsy: The Definitive Answer

If all the signs point toward melanoma -- or if the level of clinical suspicion is high -- a biopsy remains essential for a definitive diagnosis. If diagnostic uncertainty persists, consultation with a dermatologist or skin cancer specialist is a prudent intermediate step.

Regardless of the clinical pathway chosen or preferred, involve the patient in the decision. Have a thorough conversation about the clinical impressions of the skin examination and discuss the options for proceeding, including the potential harms and benefits. To improve the likelihood of patient satisfaction, make sure the decision is a shared one.

Read Part 1 of this series: Melanoma: Epidemiology, Diagnosis, and Treatment

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  Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined MedPage Today in 2007. Follow