Woman with a yellow patch on the hairy part of the head

A 52-year-old woman was referred to a dermatologist with a changed yellowish lesion on her scalp. Histological features were those of a sebaceous naevus with secondary malignant differentiation into superficial and solid basal cell carcinoma. A sebaceous naevus is a benign, congenital, hamartomatous lesion. In adulthood, secondary neoplasms may develop within them.