(A) Pilomatricoma is a well-circumscribed proliferation with basaloid keratinocytes resembling those seen in the hair bulb/matrix that transition into large masses of pink keratin material with focal calcification (H&E 20x). (B) The basaloid matrical cells abruptly keratinize into large collections of pink keratinocytes without nuclei (shadow cells) (H&E 200x).
