Pre-Malignant Skin Conditions

Question 1

Actinic keratosis (solar keratosis) clinical presentation

Answer 1

ill-defined, scaly, erythematous papules or plaques on a background of sun-damaged skin (solar heliosis)

• sandpaper-like, gritty sensation felt on palpation, often easier to appreciate on palpation rather than inspection
• sites: areas of sun exposure (face, ears, scalp if bald, neck, sun-exposed limbs)

Question 2

Actinic keratosis (solar keratosis) pathophysiology

Answer 2

• UV radiation damage to kerainocytes from repeated sun exposure (especially UVB)
• risk of transformation of AK to SCC (~1/1,000), but higher likelihood if AK is persistent
• UV-induced p53 gene mutation
• risk factors: increased age, light skin/eyes/hair, immunosuppression, syndromes such as albinism or xeroderma pigmenotsum
• risk factors for malignancy: immunosuppression, history of skin cancer, persistence of the AK

Question 3

Actinic keratosis (solar keratosis) epidemiology

Answer 3

• common with increasing age, outdoor occupation, M>F

* skin phototypes I-III, rare in darker skin as melanin is protective

Question 4

Actinic keratosis (solar keratosis) ddx

Answer 4

• SCC in situ, superficial BCC, seborrheic keratosis, cutaneous lupus erythematosus

Question 5

Actinic keratosis (solar keratosis) investigations

Answer 5

• biopsy lesions that are refracto y to treatment

Question 6

Actinic keratosis (solar keratosis) management

Answer 6

• destructive: cryotherapy, electrodessication, and curettage

• topical pharmacotherapy (mechanism: destruction of rapidly growing cells or immune system modulation)
■ topical 5-Fluorouracil cream (for 2-4 wk), Imiquimod 5% (2 times per wk for 16 wk), Imiquimod 3.75% (daily for 2 wk then none for 2 wk then daily for 2 wk) Ingenol Mebutate gel 0.015% (daily for 3 d on the head and neck), Ingenol mebutate 0.05% gel (daily for 2 d on the body)

• photodynamic therapy
• excision

Question 7

Types of AK

Answer 7

• Erythematous: typical AK lesion
• Hypertrophic: thicker, rough papule/plaque
• Cutaneous horn: firm hyperkeratotic outgrowth
• Actinic cheilitis: confluent AKs on the lip
• Pigmented: flat, tan-brown, scaly plaque
• Spreading pigmented
• Proliferative
• Conjunctival: pinguecula, pterygium

Question 8

Leukoplakia clinical presentation

Answer 8

• a morphologic term describing homogenous or speckled white plaques with sharply demarcated borders
• sites: oropharynx, most often floor of the mouth, soft palate, and ventral/lateral surfaces of the tongue

Question 9

Leukoplakia pathophysiology

Answer 9

• precancerous or premalignant condition

* oral form is strongly associated with tobacco use and alcohol consumption

Question 10

Leukoplakia epidemiology

Answer 10

• 1-5% prevalence in adult population after 30 yr of age; peak at age 50
• M>F, fair-skinned
• most common oral mucosal premalignant lesion

Question 11

Leukoplakia differential diagnosis

Answer 11

• lichen planus, oral hairy leukoplakia

Question 12

Leukoplakia investigations

Answer 12

• biopsy is mandatory because it is premalignant

Question 13

Leukoplakia management

Answer 13

• low risk sites on buccal/labial mucosal or hard palate: eliminate carcinogenic habits, follow-up
• moderate/dysplastic lesions: excision, cryotherapy