A benign tumor derived from outer root sheath epithelium of a hair follicle, consisting of cells with pale-staining cytoplasm containing glycogen; multiple trichilemmoma's are present on the face in Cowden's disease.

Cowden's disease is also known as hypertrichosis and gingival fibromatosis from infancy, it may also be accompanied by postpubertal fibroadenomatous breast enlargement; papules of the face are characteristic of multiple trichilemmomas.