Histologically this is a fairly well differentiated squamous cell carcinoma with some epithelial nests. The left side of the face, beneath the eye, is grossly swollen and the skin bears two blue grey hairless areas approx. Molar teeth on the upper left side are missing. The socket sites are occupied by an ulcerated raw mass which extends laterally into the adjacent cheek tissue. Beneath the ulcer and extending to the facial swelling seen externally is a mass of firm pale tissue.
Histological examination reveals a typical ulcerated, keratinising squamous cell carcinoma.
From a 5 year old Terrier bitch. Facial swelling had been present for 2 months producing severe ulceration of the mouth and multiple facial sinuses. Squamous cell carcinoma of the mouth are locally invasive tumours which do not commonly metastasise beyond the head. This is in striking contrast to squamous cell carcinoma arising in the tonsil. These frequently metastasise widely, often early in the history of the tumour.