A 74-year-old man is referred for evaluation of a growth on his back, which was first noted ~3 months ago. The lesion has been steadily increasing in size and has recently begun to bleed following light pressure. The patient admits to lifelong ample sun exposure but denies a prior history of skin cancer. Physical examination reveals a 3.5cm slightly violaceous nodule with crusted poles surrounded by a zone of erythema. The lesion is firmly fixed to underlying tissue. Cervical lymph nodes are not palpable.
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Over 100,000 new cases of melanoma are predicted in 2021 in the US, a statistic that includes both invasive and noninvasive lesions.1 Based on data accrued from 2016 through 2018, approximately 2.3% of men and women will be diagnosed with melanoma of the skin at some point during their lifetime.1
Risk factors for the development of melanoma include a positive family history, multiple nevi (>16 common nevi); blue, green, or hazel eye color; and red or blond hair color.2 The most important modifiable risk factor for melanoma is ultraviolet exposure. Melanoma has been linked to high amount of sun exposure, prior sunburns, and the use of indoor tanning machines.3,4
The primary treatment for melanoma is surgical excision, with a 2.0cm margin for deeper lesions considered adequate.5 Patients at risk of metastatic spread to lymph nodes may elect to undergo lymphatic mapping and sentinel-node biopsy. Approximately 50% of melanomas have BRAF mutations, which resulted in the development of the first targeted therapies.6 Noteworthy advances in the treatment of advanced disease now include 4 regimens of immunotherapy and 3 regimens of targeted therapy all of which have been shown to increase overall survival and disease-free survival.6
A shave biopsy was performed on this patient and revealed a melanoma with a Breslow thickness of at least 1.5 mm (stage II melanoma). Both mitoses and ulceration were noted. The patient underwent wide local excision with a 2.0-cm margin.
Stephen Schleicher, MD, is director of the DermDox Center for Dermatology in Pennsylvania, associate professor of medicine at Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
Greg Forsyth, PA-C, is a physician assistant at the DermDox Centers for Dermatology in Camp Hill and Mechanicsburg, Pennsylvania.
1. National Cancer Institute. Cancer Stat Facts: Melanoma of the skin. Accessed July 14, 2021. https://seer.cancer.gov/statfacts/html/melan.html
2. Chen ST, Geller AC, Tsao H. Update on the epidemiology of melanoma. Curr Dermatol Rep. 2013;2(1):24-34. doi: 10.1007/s13671-012-0035-5
3. Gandini S, Sera F, Cattaruzza MS, et al. Meta-analysis of risk factors for cutaneous melanoma: II. Sun exposure. Eur J Cancer. 2005;41(1):45-60. doi: 10.1016/j.ejca.2004.10.016.
4. Boniol M, Autier P, Boyle P, Gandini S. Cutaneous melanoma attributable to sunbed use: systematic review and meta-analysis. BMJ. 2012;345:e4757. doi: 10.1136/bmj.e4757
5. Gillgren P, Drzewiecki KT, Niin M, et al. 2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm: a randomised, multicentre trial. Lancet. 2011;378(9803):1635-1642. doi: 10.1016/S0140-6736(11)61546-8
6. Curti BD, Faries MB. Recent advances in the treatment of melanoma. N Engl J Med. 2021;384(23):2229-2240. doi: 10.1056/NEJMra2034861