Melanoma: Clinical sciences

Melanoma is a very serious type of skin cancer arising from pigment-producing cells called melanocytes. It’s the fifth most common cancer in the United States and is associated with high rates of mortality. Melanoma can develop anywhere on the body and has a high rate of spread, so early diagnosis and treatment are key to improve overall outcomes.

Alright, when a patient presents with a chief concern suggesting melanoma, the first step is to obtain a focused history and physical. Typically, patients will report noticing a skin lesion with recent changes in size, color, or developing associated symptoms like pruritus. Sometimes they might even notice bleeding from the lesion.

A patient may also experience systemic symptoms that are alarming for malignancy, including fevers, chills, fatigue, bone pain, or weight loss. History might reveal risk factors like a personal or family history of cutaneous malignancy or immunosuppression, as well as fair skin, a tendency to sunburn, chronic sun exposure, or previous sunburns.

On a physical exam, you’ll typically find a pigmented skin lesion like a macule, plaque, or nodule with an irregular border. Make sure to do a full body exam checking for other similar lesions or nevi.

Important findings can be summarized by the mnemonic ABCDE, which stands for Asymmetry; Border irregularities; Color variations, such as brown or black spots with other colors like red, blue, gray, or white; Diameter, often larger than 6 mm; and Evolution, like changes in size, shape, or color, depigmentation, development of streaks, pseudopods or irregular vascularity.

Some of the suspicious characteristics you should look for include bleeding, crusting, or ulceration. If you see a lesion that differs from other nevi, it is called the "ugly duckling sign". Last but not least, remember to check regional lymph nodes for lymphadenopathy, which is concerning for possible metastasis. If you see these findings, be very suspicious of melanoma.

Here’s a clinical pearl! Primary care settings usually perform naked-eye physical examination, while dermatologic settings may also use support diagnostic tools like a dermatoscope, which acts as a magnifying glass to help evaluate the lesion in more detail.

The best way to confirm the diagnosis is with an excisional or incisional biopsy of the lesion, which will provide histopathological information. When possible, an excisional or complete biopsy should be performed to remove the entire lesion. This is done by taking 1 to 3 mm margin of surrounding normal skin, including the depth of the thickest part of the lesion. However, this might not be feasible if the lesion is large or located on the face, palms, or ears.