20 - 110 - EPITHELIAL PRECANCEROUS LESIONS Flashcards
Precursor lesions of cutaneous squamous cell carcinoma (SCC).
ACTINIC KERATOSES
most important etiologic factor in the development of actinic keratoses
Long-term and cumulative ultraviolet (UV) radiation exposure
Risk factors of Actinic keratoses
fair skin, age, cumulative UV radiation exposure, immunosuppression, prior history of non-melanoma skin cancer

Actinic Keratoses
Multiple scaly and erythematous plaques on the dorsal hands of a 71-year-old male patient with a history of significant ultraviolet exposure. The lesions were grade II to grade III actinic keratoses.
They typically develop on sun-exposed areas, such as the balding scalp, head, neck, forearms, dorsal hands, and in women, additionally the dorsal legs (Fig. 110-1).

Mild actinic keratoses on the face of a fairskinned woman (grade I). The lesions appear as erythematous patches with a rough texture on palpation. Note other signs of actinic skin damage such as perioral wrinkling and the presence of solar lentigines.

Field cancerization. There are several ill-defined erythematous and scaly plaques, crusts, and ulcerations affecting a large area (“field”) of the balding scalp. Further alterations, such as mottled hypopigmentation and hyperpigmentation, are present and indicate actinic damage.
Alongside clinically detectable AKs, multiple subclinical lesions may be present (Fig. 110-3). This concept is known as field cancerization and is crucial for the therapeutic approach.

A, Multiple well-defined hypertrophic actinic keratoses on the decollete of a middle-aged female. B, A higher magnification reveals the rough and hyperkeratotic texture of some lesions.
main clues to the transition of AK to SCC
induration, inflammation, pain, and ulceration
type of hypertrophic AK that presents with a conical hypertrophic protuberance emanating from a skin-colored to erythematous papular base

Cutaneous horn, also known as cornu cutaneum, refers to a reaction pattern and not a particular lesion.
A, Cutaneous horn of the ear. Only biopsy will confirm whether this is an actinic keratosis or a squamous cell carcinoma. B, Cutaneous horn of the cheek.
represents confluent AKs on the lips, most often the lower lip
Actinic cheilitis
Persons with this condition have red, scaly, chapped lips, and at times erosions or fissures may be present (Fig. 110-6). The vermilion border of the lip is often indistinct, and focal hyperkeratosis and leukoplakia also may be seen. Individuals with this condition often complain of persistent dryness and cracking of the lips.

Classification of Actinic Keratosis

Olsen classification
Grade 1 includes lesions that are mild, slightly palpable, and are better seen than felt
Grade 2 represents lesions that are moderately thick and easily seen and felt.
Grade 3 lesions are severe, very thick and/or obvious AKs
Roewert-Huber classification (scheme for grading AK severity)
type AK I, atypical keratinocytes are restricted to the lower third of the epidermis and are only found within the basal and suprabasal layers.
type AK II, atypical keratinocytes are found within the lower two-thirds of the epidermis, alternating with zones of normal epidermis. In the upper papillary dermis buds of keratinocytes can be found
type AK III, atypical keratinocytes extend to the lower two-thirds of the full thickness of the epidermis. They can also involve the epithelia of the hair follicle, infundibula, and acrosyringium.
most important contributing factors for the formation of AKs.
Fair skin and exposure to UV radiation




single most effective means of decreasing the risk of AKs
Minimizing UV radiation
squamous cell carcinoma (SCC) in situ
Bowen disease (BD)



Bowenoid papulosis is a precancerous condition of the genitalia caused by infection with high-risk HPV, most commonly with types
16, 18 and 33

Epidermodysplasia verruciformis (EV) is an inherited skin condition with a high local susceptibility to infection with human papillomavirus (HPV), most commonly with HPV types ________
types 5 and 8




