Melanoma

Background

  • Ultraviolet UVB light (315 – 280 nm) from sun/tanning beds damages DNA
  • High risk in fair skin, blue eyes, and red-haired people,
  • High risk history of multiple atypical nevi or dysplastic nevi

Clinical Features

Classic melanoma.
On the left side from top to bottom: melanomas showing (A) Asymmetry, (B) a border that is uneven, ragged, or notched, (C) coloring of different shades of brown, black, or tan and (D) diameter that had changed in size compared to normal moles on the right.
  • Asymmetry
  • Borders (irregular)
  • Color (variegated)
  • Diameter (greater than 6 mm (0.24 in), about the size of a pencil eraser)
  • Evolving over time or Elevated above the skin

Differential Diagnosis

Dermatologic malignancies

Dark raised skin lesions

Evaluation

  • Biopsy outpatient at dermatology office
  • LDH (elevated indicates metastasis, particularly to the liver, not sensitive)
  • Imaging for metastasis
    • CXR or CT
    • MRI, PET and/or PET/CT scans


Type Features Incidence[1][notes 1] Photograph Micrograph
Superficial spreading melanoma Melanoma cells with nest formation along the dermo-epidermal junction. 70% File:Superficial spreading melanoma in situ on dermoscopy.jpg File:Histopathology of superficial spreading melanoma.jpg
Nodular melanoma Grows relatively more in depth than in width. 15% - 20% File:Photography of nodular melanoma.jpg File:Histopathology of nodular melanoma.jpg
Lentigo maligna melanoma Linear spread of atypical epidermal melanocytes as well as invasion into the dermis.[2] 5% - 10% File:Photograph of lentigo maligna melanoma.jpg File:Histopathology of lentigo maligna melanoma.jpg
Acral lentiginous melanoma Continuous proliferation of atypical melanocytes at the dermoepidermal junction.[3] 7% - 10% File:Photography of a large acral lentiginous melanoma.jpg File:Histopathology of invasive acral lentiginous melanoma.jpg

Disposition

  • Refer to dermatology

Prevention

  • Avoid UV radiation: hats, long sleeve shirts, sunglasses with UV protection
  • Even though tanning beds mostly UVA, still can cause melanoma
  • Sunscreen
    • Blocks damaging UVB radiation
    • Sun Protectant Factor (SPF) of 15 means if you notice a burn at 10 min, applying SPF 15 would allow you to stay out 150 min before noticing burn
    • SPF >30 if outside work or long time recreation and reapply as needed

See Also

References

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  2. ↑ Template:Cite journal Last Update: May 18, 2019.
  3. ↑ Template:Cite journal


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