trichoepithelioma (multiple)
Last reviewed 01/2018
Multiple trichoepithelioma is a rare epithelial tumour that attempts to differentiate into hair follicule cells. It is frequently dominantly-inherited and its gene has been mapped to chromosome 9p21.
After puberty, multiple skin-coloured nodules appear. Predominantly, these are on the face but they can appear on the scalp, neck and trunk. Histologically, there are multiple lacunae filled with keratin - horn cysts. There may be focal proliferations of basal cells. There may be failed attempts to form hair papillae and follicles.
Usually after a long duration, the trichoepithelioma may transform into an invasive basal cell epithelioma or carcinoma. Treatment is excision.