Mitotic figures are common. This presentation may resemble Bowen Disease or carcinoma in situ. Often, marked hyperkeratosis and areas of parakeratosis with loss of the granular layer are present. A dense inflammatory infiltrate usually is present. Quite often the invasive carcinomas that develop from these actinic keratoses are the less aggressive type and the prognosis usually is excellent.
Distant metastases are extremely rare.
The incidence is much higher in the Sun Belt and is related directly to light skin and sun exposure. They may smolder for years before they advance into a carcinoma in situ. Once they break through into the dermis, they become invasive carcinomas, which rarely can metastasize and cause death. The incidence is much higher in individuals with fair skin and blue eyes and is lower in darker skin types. It is relatively nonexistent in black skin.