A20. Precancerous lesions and intraepidermal carcinoma
- Precancerous lesions
- Lentigo maligna
- Actinic keratosis
- Cutaneous horns
- Leucoplakia
- Intraepidermal carcinoma/carcinoma in situ
- Bowen disease
- Erythroplasia of Queyrat
- Paget disease
Lentigo maligna
- Precancerous lesion of dysplastic melanocytes
- Occurs in elderly
- Risk factor: UV exposure
- Darkly pigmented macule
- On sun-exposed areas
- Face, neck
- Irregular borders
- 1 mm – 2 cm
- Irregular colour
- On sun-exposed areas
- Treatment
- Surgical excision with safety margin
Actinic keratosis
- Precancerous lesions of squamous cells
- Occurs in elderly with light skin
- Risk factor: UV exposure
- Clinical features
- Small lesion with rough surface
- -> lesion grows and becomes erythematous and scaly
- On sun-exposed areas
- May develop into a cutaneous horn
- Treatment
- Few lesions
- Cryotherapy
- Many lesions
- 5-FU
- Imiquimod
- Prevention with sunscreen
- Few lesions
Leucoplakia
- Hyperkeratosis and dysplasia of epithelium and mucous membranes
- Risk factors
- Smoking
- Alcohol
- Clinical features
- White plaque that cannot be scraped off
- Most commonly in oral cavity
- Differential diagnosis
- Oral candidiasis
- Oral hairy leukoplakia
- Treatment
- Avoidance of risk factors
- Cryotherapy
Bowen disease
- Squamous cell carcinoma in situ of skin
- Risk factors
- UV exposure
- HPV 16, 18
- Arsenic
- Clinical features
- Erythematous and scaly lesion
- Irregular shape, sharp borders
- On sun-exposed areas
- Treatment
- 5-FU
- Imiquimod
Erythroplasia of Queyrat
- Erythroplasia of Queyrat = Bowen disease of glans penis
- Squamous cell carcinoma in situ of penile mucosa
- Risk factors
- Chronic inflammation
- HPV 16, 18
- Clinical features
- Sharply demarcated, non-healing plaques or papules
- May ulcerate or bleed
- Treatment
- 5-FU
- Imiquimod
Paget disease of the breast
- Ductal carcinoma in situ of the nipple and areola
- Clinical features
- Erythematous, scaly, vesicular rash
- Pruritus
- Burning
- Treatment
- Surgical removal