Melanoma: Frontline clinicians play a vital role in early detection

About Melanoma

Melanoma is an aggressive malignancy of melanocytes. The etiology of melanoma is incompletely understood, but ultraviolet radiation and genetics are believed to play a role.

Melanoma may arise wherever there are melanocytes including on the skin, on mucous membranes (eg, mouth, male and female genitals), around or under the nail apparatus (eg, subungual melanoma), and in the eye (eg, conjunctival, choroidal, and iris melanoma).

There are 4 main subtypes of cutaneous melanoma: superficial spreading melanoma (the most common type), nodular melanoma, lentigo maligna melanoma, and acral lentiginous melanoma (the least common type). Amelanotic melanoma is a clinical subtype of cutaneous melanoma with little to no pigment on visual inspection.

Early melanoma is highly curable. More advanced cases require multidisciplinary input and surgical and medical therapeutic approaches. Frontline clinicians and other health care professionals can play a vital role in prevention and early detection by:

• Identifying risk factors
• Evaluating lesions brought to clinical attention by patients
• Examining the skin while performing the physical exam and identifying concerning lesions
• Deciding when patients need referral to a dermatologist

Identifying Risk Factors

Risk factors for melanoma include the following:

• A family history or prior personal history of melanoma
• A history of severe or blistering sunburns
• A changing nevus
• A giant congenital nevus
• Older age
• A lighter skin phototype
• Multiple atypical nevi

Evaluating Lesions

Careful skin examination is important in identifying concerning lesions that patients may ask about or that you may identify on your examination. Individual pigmented lesions can be assessed during the physical examination by applying the ABCDEs of melanoma and the “ugly duckling” rule.

The ABCDEs of melanoma:

A – Asymmetry: One half of the lesion does not mirror the other half.
B – Border: The borders are irregular or indistinct.
C – Color: The color is variegated; the pigment is not uniform, and there may be varying shades and/or hues.
D – Diameter: Classically, any pigmented lesion greater than 5-6 mm in diameter is concerning, although melanomas may also be smaller.
E – Evolving: Notable change in a lesion over time raises suspicion for malignancy. Ulceration and bleeding should prompt biopsy.

This image of a melanoma demonstrates several features of the ABCDEs. We can see that this melanoma is asymmetrical, has irregular borders and multiple colors present, and is definitely larger than the head of a pencil. A careful history would also reveal evolution over the past weeks and months.

The ugly duckling rule:

If a patient has multiple pigmented lesions, look for any lesion that stands out from the rest or is unlike the others.

Referral to a Dermatologist

Refer promptly to a dermatologist if you suspect melanoma, including those pigmented lesions that fulfill one or more of the ABCDE criteria or for “ugly ducklings”. The dermatologist will biopsy any lesion that is suspicious for melanoma. Surgical excision is the treatment of choice for thin (early) melanomas. For deeper (more advanced) melanomas, sentinel lymph node biopsy and imaging may be needed for further work-up and to guide therapy. For these deeper melanomas, therapy decisions are often made by multidisciplinary teams comprising dermatologists, and surgical, medical, and radiation oncologists.

Dermatology referral should also be placed for patients with hundreds of nevi, or for many nevi that are atypical or heterogeneous in appearance. First-degree relatives of individuals with melanoma should have a skin check performed annually per current guidelines.

Prevention

• Counsel patients on sun protection.
• Teach patients to check their own skin for suspicious moles that fulfill the ABCDE or ugly duckling criteria, including less visible areas of the body such as the back, legs, and soles of feet.