KERATOACANTHOMA

Question 1

KERATOACANTHOMA

Lesion

Answer 1

rapidly growing, firm, dome-shaped, erythematous or skin-coloured nodule with central keratin-fillled
crater, resembling an erupting volcano
• may spontaneously regress within a year, leaving a scar

Question 2

KERATOACANTHOMA

sites

Answer 2

sun-exposed skin

Question 3

KERATOACANTHOMA Pathophysiology

Answer 3

epithelial neoplasm with atypical keratinocytes in epidermis

• low grade variant of SCC

Question 4

KERATOACANTHOMA Etiology

Answer 4

HPV, UV radiation, chemical carcinogens (tar, mineral oil)

Question 5

KERATOACANTHOMA Epidemiology

Answer 5

> 50 yr, rare <20 yr

Question 6

KERATOACANTHOMA

Differential Diagnosis

Answer 6

treat as SCC until proven otherwise

• nodular BCC, Merkel cell carcinoma, hypertrophic solar keratosis, verruca vulgaris

Question 7

KERATOACANTHOMA Management

Answer 7

surgical excision or saucerization (shave biopsy) followed by electrodesiccation of the base, treated
similarly to SCC
• intralesional methotrexate injection