title: Follicular germinative cells in pilomatricoma.
abstract: Pilomatricoma is a follicular neoplasm that shows differentiation towards the follicular matrix, as characterized by matrical cells and shadow cells. In addition, this is sometimes accompanied by differentiation toward the follicular infundibulum and outer root sheath. These finding suggest that pilomatricoma can subtly differentiate towards any structure of the follicle. However, morphologically, no distinct germinative cells resembling embryonic follicular germ cells have been found in pilomatricoma to date. We report on two cases of pilomatricoma in which distinctive follicular germinative cells palisaded at the edges of collections of matrical cells. We propose two explanations: one is that the metrical cells of pilomatricoma can focally de-differentiate to form follicular germinative cells, and the other is that these follicular germinative cells are the precursor cells of pilomatricoma.
authors.affiliation: Department of Dermatology, Kin-ikyo Central Hospital, Sapporo, Japan. wataru@seagreen.ocn.ne.jp
authors.forename: Wataru
authors.initials: W
authors.lastname: Nishie
authors.forename: Tetsunori
authors.initials: T
authors.lastname: Kimura
mesh_terms: D000328:Adult; D001132:Arm; D002648:Child; D005260:Female; D006201:Hair Diseases / Q000473:pathology*; D018859:Hair Follicle / Q000473:pathology; D006801:Humans; D018296:Pilomatrixoma / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*