Acquired hypertrichosis lanuginosa: case report and review of the literature.

Acquired hypertrichosis lanuginosa is a rare cutaneous disorder usually associated with internal malignancy that consists of the development of abnormal hair growth of the lanugo type, often confined to the skin of the face and neck, although other areas also may be involved. We report on a 66-year-old woman with a metastatic ductal infiltrating carcinoma of the breast who developed growth of fine lanugo type hair on her face and progressive growth of the hair of eyebrows and eyelashes. We review the literature on this uncommon paraneoplastic cutaneous disorder emphasizing the pathogenic mechanisms that have been proposed to explain the striking overgrowth of lanugo type hair.