+ General Considerations

  • Benign epithelial proliferation arising from superficial epithelium between hair follicles
  • Small to moderate size with pore containing keratin ± hair follicles
  • Rupture produces a severe pyogranulomatous dermatitis due to the keratin contents of the cyst
  • Cytology: keratinous debris, clusters of squamous cells ± cholesterol crystals
  • 1 case reported in the cat
  • Intracutaneous cornifying epithelioma is common in dogs
  • Sex predisposition: males
  • 2 distinct clinical patterns for intracutaneous cornifying epithelioma: solitary and generalized

+ Solitary Intracutaneous Cornifying Epithelioma

  • Solitary form is more common in purebred dogs along the back, neck, thorax, and shoulders
  • Treatment: surgery
  • Prognosis: good

+ Generalized Intracutaneous Cornifying Epithelioma

  • Norwegian Elkhound and Keeshond are predisposed to the generalized or multicentric form
  • Treatment: cryosurgery or retinoids (etretinate is better than isotretinoin)
  • Prognosis: guarded to good with 71% complete response and 29% to retinoids, but recurrence is common following cessation of treatment