Malignant pilomatricoma in 3 dogs.
Malignant pilomatricoma, also known as pilomatrix carcinoma and calcifying epitheliocarcinoma (in the human literature), has been considered a rare neoplasm of dogs. The authors present 3 canine cases of malignant pilomatricoma (2 with distant metastasis) and compare its behavior with reported behavior. Cases include an 8-year-old spayed female Airedale Terrier, a 7-year-old male Bassett Hound, and a 12-year-old intact male Giant Schnauzer. In all cases, the histologic features included trabeculae of basaloid cells, abrupt keratinization, "ghost" or "shadow" cells, and various features of malignancy consistent with a diagnosis of malignant pilomatricoma. Metastasis, including that to bone, was confirmed in 2 cases. Four cases of the 13 canine pilomatricomas diagnosed within a 24-month period (2006-2008) at the Ohio State University (2 of which are discussed in this report) were classified as malignant, which suggests that malignant pilomatricoma is more common than previously reported.
Carroll
E E
EE
Armed Forces Institute of Pathology, Washington, DC, USA. erica.carroll@med.navy.mil
Fossey
S L
SL
Mangus
L M
LM
Carsillo
M E
ME
Rush
L J
LJ
McLeod
C G
CG
Johnson
T O
TO
D000818:Animals; D001859:Bone Neoplasms / Q000556:secondary / Q000601:surgery / Q000662:veterinary*; D004283:Dog Diseases / Q000473:pathology* / Q000601:surgery; D004285:Dogs; D017809:Fatal Outcome; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D018296:Pilomatrixoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D012878:Skin Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*