Melanoma (Cutaneous)

50 y/o white M with h/o extensive UV exposure and moles/dysplastic nevi presents with a hyperpigmented, macular skin lesion on trunk. Lesion has recently increased in shape, size, and appearance. Positive family h/o cutaneous melanoma. Flat/palpable hyperpigmented macule with asymmetric/irregular borders, color variation, and diameter > 6mm on exam.

• Dermoscopy reveals asymmetric color distribution and starburst pattern.

• Scoop shave biopsy positive for melanoma

• Refer to surgery for melanoma resection with margins per Breslow depth

• Lesion depth greater than 1.0 mm; refer for sentinel lymph node biopsy to determine stage/prognosis

Notes

• Epidemiology

  • 3 to 5% of all skin cancers

  • Responsible for 75% of skin cancer deaths

  • At-risk populations

    • Most cases occur in white males > 65 years

    • Most common cancer in women age 25-29 years

• Subtypes include superficial spreading, nodular, lentigo, amelanotic, acral-lentiginous, subungual

  • Superficial spreading

    • Most common subtype (70% of melanomas)

    • Occur between ages 30-50 years

    • Typically located on trunk in men and legs in women

  • Nodular

    • Second most common subtype (10-15%)

    • Generally occur in men on the trunk, head, or neck

• Diagnosis

  • ABCDE: Asymmetry, border irregularities, color variation, diameter, and evolution

  • Dermatoscope

    • Device used to magnify lesion under polarized light

    • Increases diagnostic accuracy by 10-27%

  • Biopsy: Scoop shave or punch biopsy can be performed

  • Breslow depth: Histopathologic depth of lesion used to determine prognosis and surgical margins

• Surgical margins

  • Per Breslow depth

    • In situ = 5 mm margins

    • 2.0 mm depth or less = 1 cm margins

    • > 2.0 mm depth = 2 cm margins

  • Narrow (1-2 cm) vs. wide surgical margins (3-5 cm) do not impact survival