Efi. Gelerstein 2011

Topic 25. Praecancerous lesions and intraepidermal carcinomas

Classification1. Benign tumors2. Premalignant lesions → Precancerosis 3. In situ (intra-epidermal) cancers 4. Malignant tumors

Premalignant lesions → Precancerosis 1. Epithelial precancerous lesions2. Precancerous Keratinocytic Lesions

a. Actinic keratosis = SOLAR KERATOSESb. Arsenical keratosisc. Tar keratosisd. Chronic radiation keratosise. Chronic scar keratosisf. Reactional keratosisg. PUVA keratosish. Viral keratosis

Bowenoid papulosis Epi-dermodysplasia verruciformis

i. Keratoacanthoma (20% invasive SCC)

Epithelial precancerous lesions Precancerous / premalignant lesion is one that has a strong chance of malignant transformation. Histopathologically demonstrate atypical confined to the epidermis.

Precancerous Keratinocytic Lesions1. Actinic keratosis (keratoma senilis)

Cutaneous neoplasms consisting of proliferations of cytological aberrant epidermal keratinocytes that develops in response to prolonged exposure to ultraviolet radiation.

Third most common reason in dermatological practice!! Elderly, fair-skinned, light-eyed individuals are the most important risk

population History of significant sun exposure Burned and freckled rather than tanned (Skin phototypes I-II-III.) Localization : chronically sun-exposed sites of the body. 2-6 mm, erythematous, flat rough or scaly papule

Other clinical subtypes of actinic keratoses (keratoma senilis) Hypertrophic AK (keratoma)- thicker scaly, rough papule or plaque Cutaneous horn (cornu cutaneum)

2. Arsenical keratosis

Efi. Gelerstein 2011

Association with chronic arsenicism → Arsenic exposure:- Medicinal : (syphilis, psoriasis, asthma, tripanosomiasis)- Occupational : (agricultural, computer microchip, glass industries)- Environmental : (contaminated water)

Mean latency periods: 9-30 years Pinpoint papules : „easier felt than seen” Punctate, yellow, keratotic papules on palms and soles in areas of constant pressure or repeated

trauma Other cutaneous neoplasms associated

- Bowen’s disease, BCC, SCC, MCC- Merkel cell carcinoma

4. Chronic radiation keratosis Late side effects of radiation therapy Late radiation ulcer/ Carcinoma in scars

5. Chronic scar keratosis

8. Viral keratosis Bowenoid papulosis Pigmented verrucous papules on genitalia HPV infection : (16, 18, 31-35) Histopathologically : SCC in situ-like changes Course : from spontaneous regression to transformation into Bowen

disease and invasive SCC

9. Keratoacanthoma Sun-exposed skin Rapid growing (few weeks) Enlarging erythematous, symmetric, firm nodule with a central

keratotic core Slow spontaneous involution - leaving on hypo-pigmented scar

Efi. Gelerstein 2011

Xeroderma pigmentosumAutosomal recessive inherited disorder characterized by the defective repair of DNA after sun damage.

Actinic cheilitis Most often on lower lip Red, scaly, chapped lips Erosions and fissures may be present

Leukoplakia Older male – long standing tobacco use and / or alcohol abuse Chronic, fixed, white lesion of the oral or anogenital mucosa Asymmetric, asymptomatic Transform into cancer Oral leukoplakias carry a 5-25% risk of dysplasia or malignancy!!

In situ (intra-epidermal) cancers1. Bowen’s disease2. Erythroplasia Queyrat3. Mammary and extra-mammary Paget’s disease

Bowen’s disease Form of SCC in situ Affects both skin and mucous membranes Potential to progress into invasive SCC Etiological factors :

1. Chronic sun exposure2. Arsenic exposure3. Ionizing radiation4. Immunosuppression5. Viruses (certain types of HPV)

Slowly enlarging, pink to brownish, thin psoriasiform plaque with well-demarcated, irregular borders, overlying scale or crust

Differential diagnosis : psoriasis, parasitic eczema, superficial basal cell carcinoma Histology : full-thickness atypical of the epithelium and lack of maturation

Efi. Gelerstein 2011

Erythroplasia of Queyrat In situ SCC affecting the mucosal surfaces of the penis Glistening, red, velvety plaque on glans, prepuce, urethra Persist and enlarge slowly Localized pain, pruritus, difficulty retracting the foreskin, bleeding,

crusting Biopsy – histology!!! 33% invasive SCC!!

Paget’s disease Rare intra-epidermal adenocarcinoma Mimic inflammatory or infectious conditions Unilateral, sharply demarcated, erythematous or scaly patch on the nipple or areola with variable

extension to surrounding skin Mammary Paget’s often associated with an underling carcinoma of the breast (50% palpable CC) Biopsy-histology!!!