Skin - Actinic keratosis

Also called solar keratosis or senile keratosis
Exposure to sunlight. On sun-exposed sites (face, arms, dorsum of hands)
● Called actinic cheilitis in lips
● May become invasive with only a single layer of atypical keratinocytes
Risk factors:● Fair skin, ionizing radiation, hydrocarbon or arsenic exposure, renal transplant

                                                                                                                                                               

Actinic keratosis  (a) One of the first clues to the diagnosis  is the discontinuity of the parakeratosis as the dysplastic process spares adnexal structures. Note the lack of parakeratosis over the sebaceous gland. This specimen also demonstrates dense dermal elastosis (b)  keratinocyte dysplasia confined to the lower third of the epidermis (200x). (c) A more established lesion of AK demonstrating nearly full thickness keratinocyte dysplasia and prominent budding of the basal layer into the superficial dermis

Treatment:

● Curettage, cryotherapy, topical chemotherapeutic agents (Imiquimod, 5-FU)