Actinic keratosis

    Article Contributors: 
    Sean Klepper M.D.
    Artur Zembowicz M.D....

    Clinical Features:

    • Common preneoplastic lesion most often seen on sun-exposed skin of the elderly
    • Approximately 1 in 1000 untreated actinic keratoses eventually evolve into squamous cell carcinoma, and patients with actinic keratoses have a markedly increased risk of developing squamous cell carcinoma.
    • Risk factors include prolonged skin exposure and fair skin.
    • Most commonly presents as a small, well-demarcated hyperkeratotic growth, with several described variants which are associated with their own clinical appearances.

    Histologic Features:

    • Hyperparakeratosis, often with loss of the granular layer
    • Proliferation of the basal layer with slight budding into the dermis
    • Basal layer atypia: increased mitoses, enlarged nuclei with prominent nucleoli, increase or decrease in basophilia compared to surrounding keratinocytes
    • There is often mild spongiosis above the atypical basal layer.
    • Liquefactive degeneration of the basal layer may occur.
    • Focal to widespread acantholysis may occur.
    • Mild upper dermal perivascular lymphocytic infiltrate
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    Cases associated with this book:

  • Actinic keratosis
    Author: Artur Zembowicz M.D. Ph.D.

    Conference: Teaching Collection