Actinic keratosis
Develops on sun-exposed skin of fair-skinned, middle-aged individuals.
Irregular hyperkeratosis surface plaque parakeratosis and acanthosis. Actinic elastosis in substantia propria. Chronic inflammatory cell infiltrate in superficial dermis.
Pre-cancerous squamous lesion, with risk of transformation and metastatic dissemination 0.5 - 3.0%.