Review Question - QID 101308

Actinic keratosis appears as a dry, scaly, hyperkeratotic papule and precedes the development of squamous cell carcinoma (SSC).

Actinic keratoses are in general small, dry, scaly, hyperkeratotic papules on an erythematous base that occur on sun exposed areas. Histologically, they are characterized by hyperkeratosis (hyperplasia of the stratum corneum) and parakeratosis (abnormal retention of cellular nuclei in the stratum corneum). These lesions can be treated with destructive therapies (e.g. chemical, freezing, burning).

Stulberg et al. review actinic keratoses and the development of SCC. They describe actinic keratoses as scaly hyperkeratotic patches that are raised and can easily palpable. SCCs arising from actinic keratoses become larger, increasingly nodular and erythematous.

Rowert-Huber et al. write that actinic keratosis is a clinical diagnosis, not a histopathologic diagnosis. Actinic keratois is useful as a clinical description because it is consistent with SCC in situ.

Illustration A displays a classic actinic keratosis on the forehead. Note the dry, scaly, hyperkeratotic papule on an erythematous base.
Illustration B displays an example of squamous cell carcinoma for comparison. Note the ulcerations and heaping of the margins.

Incorrect answers:
Answer 1: A hamartomatous lesion of sebaceous glands describes a nevus sebaceous, a precursor to basal cell carcinoma.
Answer 3: A single large pink patch describes a herald patch, the first sign of pityriasis rosea.
Answer 4: Dermatophyte infection is not associated with development of SCC.
Answer 5: UVB and UVA are associated with the development of skin cancer, not UVC.