HEAD AND NECK TUMORS OF CATS, AN OVERVIEW
by Dr. Alice Villalobos
of The Animal Cancer Center
in Hermosa Beach, California.

Until proven otherwise, most bony deformities of the face or irregular abnormal growths in the oral cavity and under the tongue of your feline patients are due to squamous cell carcinoma (SCC). Occasionally a cat will present with difficultly swallowing and a swelling along the neck due to SCC of the esophagus.

Crypto and periodontal disease will occasionally mimic SCC by producing a firm nonpainful hard swelling. In fact the typical history of a cat presented to our service with oral cancer includes a dentistry within the past two months which involved removal of loose teeth at the tumor site. Oral eosinophillic granuloma complex and stomatitis may look proliferative and angry enough to mimic SCC; however, biopsy will soon distinguish these more manageable conditions from neoplasia.

Outdoor cats with pink ears, eyelids, noses and exposed temporal skin are at high risk for solar induced SCC. Pet owners will often talk themselves into thinking the cat has a sore for six months because he bumps his nose on the screen door or gets into fights.

Ceruminous gland adenocarcinoma occasionally may obstruct the ear canal with a cauliflower like surface. Salivary gland adenocarcinomas may also appear just below the ear canal in the parotid salivary gland causing a subcutaneous nodular firm mass which will generally metastasize to the chest over a six to nine month period.

Thyroid adenomas and adenocarcinomas appear as small palpable nodules on either side of the trachea in the area of the thyroid glands and may extend caudally toward the thoracic inlet. Associated signs of hyperthyroidism such as weight loss, polyphagia, rapid heart rate, hypertension or renal disease generally accompany a high T4 value.

Atypical focal lymphosarcoma (LSA) may originate in the nasal cavity, behind the orbit or in the eye causing hypopyon. LSA has the potential to appear anywhere in the head and neck area of cats since one in five cats infected with FeLV will develop either a hematopoietic or a lymphoid neoplasia which may invade any tissue from the skin to the CNS. FIV related sub mandibular lymphadenopathy with or without uveitis or anemia may also be presented.

Fibrosarcomas (FSA), osteosarcomas (OSA) and respiratory adenocarcinomas may also be found in the nasal cavity in cats. FSA and OSA are also occasionally diagnosed in the maxilla and mandible of cats as well.

Vaccine induced FSA may involve the dorsal neck area as well as the interscapular space. These are thought to be unrelated to the aggressive multifocal fibrosarcomas we see in young cats infected with FSV.

Mast cell tumors may often originate as small dermal fleshy lesions in the facial area as well as on the pinna.

Malignant melanoma is rare, however it has been documented in the eye, periorbital tissues and skin in the feline.

A few articles follow which discuss therapy for the most common and frustrating of feline head and neck tumors.