title: Fine needle aspiration cytology of pilomatricoma in three dogs.
abstract: BACKGROUND
  Fine needle aspiration cytology is being used for the diagnosis of various neoplasms, but we are unaware of reports dealing with the cytologic features of canine pilomatricoma.
  
  
  OBJECTIVE
  The purpose of this report was to describe the cytologic features of pilomatricoma in 3 dogs.
  
  
  METHODS
  Fine-needle aspirates were obtained from cutaneous masses using a 25-ga needle. Smears were prepared and stained with May-Grünwald-Giemsa and hematoxylin and eosin. The cutaneous masses were excised and routinely processed for histologic examination.
  
  
  RESULTS
  Cytologic features of all 3 tumors included high cellularity and numerous clusters of tightly arranged of basaloid cells with evenly distributed chromatin and small distinct nucleoli surrounding sheets of "ghost cells". Ghost cells were characterized by a central unstained zone corresponding to the site previously occupied by the nucleus. Amorphous keratinized material was observed in 1 tumor. Histopathologic findings confirmed the diagnosis of pilomatricoma in all 3 cases.
  
  
  CONCLUSIONS
  Basaloid cells in association with ghost cells are important cytopathologic criteria that may provide a definitive cytologic diagnosis of pilomatricoma in dogs, and may help avoid a false diagnosis of malignancy.
authors.affiliation: Clinica Veterinaria S. Antonio, via Montale n degrees 2, 25087 Salo (BS) Italy. carsila@numerica.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Masserdotti
authors.forename: Federica Annamaria
authors.initials: FA
authors.lastname: Ubbiali
mesh_terms: D000818:Animals; D001707:Biopsy, Needle / Q000662:veterinary; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis* / Q000473:pathology; D004285:Dogs; D005260:Female; D006201:Hair Diseases / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D008297:Male; D018296:Pilomatrixoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D013194:Staining and Labeling / Q000662:veterinary