The incidence of melanoma in the United States continues to increase.1 Although melanoma accounts for a small percentage of skin cancer cases, it is responsible for the majority of skin cancer deaths.1 The clinical presentation of melanoma varies between patients, stage of diagnosis, subtype, and may initially present the same as any other pigmented macule or patch on the skin.2,3 Therefore, various methods have been implemented in order to increase awareness and aid both patients and providers in early recognition of lesions that are suspicious for melanoma.3,4 Patients can play a key role in noticing these changes as the presentation or evolution of these lesions may be very subtle.4 Routine self-skin exams are encouraged to expedite identification and proper treatment for improved prognosis.4
Who is most at risk for melanoma?
Phenotypic features of patients who are at the highest risk of melanoma include fair skin, red or blonde hair, and blue eyes.5 Interaction between both environmental and genetic risk factors are believed to be responsible for the development of melanoma.5
As with all skin cancers, the most significant environmental risk is exposure to natural and artificial ultraviolet (UV) radiation.5 Early sun exposure and sunburn during childhood has been found to double the risk of melanoma diagnosis in adulthood.5 The risk is further increased with short, intense episodes of burning and the accumulation of total UV exposure throughout a lifetime.5,6 Artificial UV radiation, such as tanning beds, yield a clinically significant risk increase, particularly in women <45 years old.7.8
Genetic risk factors can be assessed through a detailed history of skin cancer in the patient and their first-degree relatives.9,10 A history of melanoma onset in younger individuals, several relatives with a history of melanoma, multiple primary melanomas in an individual, or the presence of both pancreatic cancer and melanoma may suggest a hereditary melanoma syndrome.10 Provider should include exposure to sun and artificial UV radiation, history of sun burns, and a family history of skin cancer as indications as to which patients are at a higher risk for melanoma.
How do I know what to look for?
The ABCDE method uses analytic criteria to raise awareness for early detection of lesions that are suspicious for melanoma.4 The criteria include asymmetry, border irregularity, unevenness of color or a very dark color, diameter > 6 mm, and evolution, which includes appearance of a new lesion or a change in the appearance of an existing lesion.4 It is important to note that satisfying all 5 criteria does not guarantee a diagnosis of melanoma; lesions should be considered suspicious despite not meeting all the criteria.4 Therefore, the ABCDE criteria is intended only as general guidance to raise suspicion for irregular melanocytic lesions.4
The “ugly duckling sign”was later developed as an alternative method to lower the threshold for suspicion of a melanoma lesion.4 It has been found to be more reliable than the ABCDE method by focusing on the appearance of the lesion in comparison to other nevi on the patient’s body, rather than satisfying specific criteria.4 In this method, the lesion most unlike others on the patient’s body is the most suspect for malignancy.4 Some providers have combined these 2 methods as the “ABCDEF” method in which F stands for “funny-looking.” 4 No quantitative results have been published for the efficacy of this combination, but it seems to be well-received by patients and is expected to provide more thorough patient education.4
Additional criteria included in less frequently used methods include inflammation, crusting or oozing, and pruritis or altered sensation. Both patients and providers should be aware any lesion that meets multiple criteria or is considered an “ugly duckling” should be further evaluated for melanoma.4,7
The clinical presentation of melanoma varies between patient, stage of diagnosis, and subtype. The most common subtypes of melanoma in descending order include superficial spreading (70%), nodular (15%-30%), lentigo maligna (10%-15%), and acral lentiginous (< 5%).10
- Superficial spreading melanoma has the most well-known presentation as a variably elevated and pigmented macule or thin plaque with an irregular border and enlarging diameter. This subtype appears most commonly on the posterior trunk of men and the posterior trunk or legs of women.
- Nodular melanoma appears as an elevated, symmetrical, and melanotic lesion with a round border. However, early detection of this subtype is challenging as the lesion may initially present as amelanotic and uniform in color with a symmetric border and relatively small diameter, thereby appearing as a benign lesion.
- Lentigo maligna melanoma appears on chronically sun-damaged areas of the skin, most commonly the head and neck of older individuals. These lesions are variably pigmented with various shades of brown, a smooth surface, and an irregular border. As the lesion gradually enlarges over years, it may develop variable pigmentation, irregular shape, and raised areas as the depth of invasion increases.
- While the other subtypes of melanoma predominately appear on fair-skinned populations, acral lentiginous melanoma appear as dark brown to black, irregularly pigmented macules or patches on the palmar, plantar, and subungual surfaces of darker-skinned individuals. Variations such as change in elevation, ulceration, bleeding, or enlarging diameter signify a deeper invasion of the lesion. Therefore, it is important for providers to carefully inspect the nail beds, palms, and soles of all patients, especially patients of color, for acral lentiginous melanoma.10-12
Why is early detection so important?
Early detection of melanoma has a profound impact on the ability to effectively manage the disease and maximize the likelihood of patient survival. The chance of recovery is significantly higher in early stage melanoma that can be cured with local excision than higher stage melanoma.13,14 There is a significant decrease in 5 year-survival rates from melanoma diagnosed at stage I vs stage II and III.13 The main prognostic factor at the time of diagnosis is the median thickness of the lesion.13 A decreased thickness at the time of diagnosis has been strongly correlated with the performance of regular self-skin exams by patients and routine visits with a physician.4 In addition to the decreased mortality rate, other benefits of early detection include a reduced cosmetic effect, absence of adverse effects secondary to systemic therapies, and reduced overall health care costs.3
The patient in this case was routinely seen by several providers. The patient had a melanoma lesion on his back that went undetected long enough for the cancer to silently disseminate throughout his entire body. Had his cardiologist lifted his shirt during his consultation, or if his primary care physician educated the patient on the early warning signs for melanoma, or his dermatologist demonstrated a self-assessment for irregular macules, the patient may have had a different outcome than the reality of this case.
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