Hair shafts in epidermoid cysts.

17 cases of epidermoid cysts with vellus hairs in their lumen are reported. The clinical diagnosis was usually cysts. In 12 cases the lesions were solitary and in 5 they were multiple, small and closely set. Microscopically, the findings of the wall were those of the epidermoid cyst containing in their lumen hair shafts of lanugo size. The solitary variety of these cysts can be considered as the solitary counterpart of the eruptive vellus hair cyst. Problems of differential diagnosis are discussed.