[A malignant pilomatrixoma in the tonsillar area of a dog]

This case report discusses a 12-year-old West Highland White Terrier presented to the veterinary clinic with reverse sneezing and oral dysphagia. The endoscopic examination of the upper respiratory tract revealed a mass in the area of the right tonsil. Histologic examination confirmed the diagnosis of a malignant pilomatrixoma. The dog underwent surgical cytoreduction, followed by radiation therapy. After the treatment, the dog was free of clinical signs for 154 days and in good general condition. Due to recurrence of signs and the suspicion of clinically overt metastases in the mandibular lymph nodes, the dog was euthanized 261 days after the diagnosis. This is the first report of a malignant pilomatrixoma in the tonsillar area that has been treated with cytoreductive surgery and radiation therapy.