Trichilemmoma

  • Neoplasm with differentiation toward follicular outer sheath
  • Presents as solitary or multiple smooth-surfaced or verrucoid papules or nodules on face
  • Histology: downward lobular growth of epidermis consisting of pale or clear keratinocytes, periphery of lobules with palisading basal keratinocytes and eosinophilic hyaline membrane
  • Multiple trichilemmomas seen in Cowden disease