Sean Klepper M.D.
Artur Zembowicz M.D....
- 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.
- 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