Page 477 - Small Animal Internal Medicine, 6th Edition

CHAPTER 29 Disorders of the Oral Cavity, Pharynx, and Esophagus 449

and can cytologically resemble fibrosarcomas, carcinomas, Clinical Features
or undifferentiated round cell tumors. Biopsy and subse- Dysphagia, halitosis, anorexia, and/or bleeding are common
VetBooks.ir quent histopathologic analysis may be required for a defini- Diagnosis
features of these tumors.
tive diagnosis.
Treatment and Prognosis A large, deep biopsy specimen is needed because it is crucial
The preferred therapeutic approach in dogs with confirmed to differentiate malignant tumors from eosinophilic granu-
malignant neoplasms of the oral cavity and lack of clinically lomas. The superficial aspect of many oral cavity masses is
detectable metastases is wide, aggressive surgical excision ulcerated and necrotic because of proliferation of normal
of the mass and surrounding tissues (e.g., mandibulectomy, oral bacterial flora, making it difficult to accurately diagnose
maxillectomy) and/or radiation. Enlarged regional lymph a mass when deep tissue samples are not obtained.
nodes should be excised and evaluated histopathologically,
even if they are cytologically negative for neoplasia. Early Treatment
complete excision (especially gingival or hard palate squa- Surgical excision is desirable, but cats often do not tolerate
mous cell carcinomas and acanthomatous epulides) may be aggressive oral surgery as well as dogs do. Long-term or
curative. Sometimes, fibrosarcomas can be cured if diag- permanent feeding tubes may be required. Radiation therapy
nosed early and resected completely (i.e., 3 cm margins). and/or chemotherapy may benefit cats with incompletely
However, young Labrador Retrievers and Golden Retriev- excised squamous cell carcinomas not involving the tongue
ers in particular tend to have a histologically low-grade but or tonsil.
biologically high-grade subtype of fibrosarcoma, which has
a very high metastatic rate. Melanomas have metastatic rates Prognosis
of 60% to 80%, making surgical cure extremely rare. Rostral In general, the prognosis for cats with oral squamous cell
tumors tend to have a better prognosis, probably because they carcinoma is poor (see Chapter 81).
are diagnosed earlier than more caudal tumors. Acanthoma-
tous ameloblastomas may respond to radiation therapy alone FELINE EOSINOPHILIC GRANULOMA
(complete surgical excision is preferred), and squamous cell
carcinomas or fibrosarcomas with residual postoperative Etiology
disease may benefit from postoperative adjunctive radiation The cause of feline eosinophilic granuloma is uncertain.
therapy. Lingual squamous cell carcinomas affecting the base Hypersensitivity reactions are thought to be responsible, and
of the tongue and tonsillar carcinomas have a very poor a genetic predisposition has been suggested.
prognosis; complete excision or irradiation usually causes
severe morbidity. Melanomas metastasize early and have a Clinical Features
very guarded prognosis. Chemotherapy is usually not ben- Feline eosinophilic granuloma complex includes indolent
eficial in dogs with squamous cell carcinoma, acanthoma- ulcer, eosinophilic plaque, and linear granuloma, but it has
tous ameloblastomas, or melanoma. Piroxicam can palliate not been established that these diseases are related. Indolent
some patients with squamous cell carcinoma. Combination ulcers are classically found on the lip or oral mucosa (espe-
chemotherapy may palliate some dogs with fibrosarcomas cially the maxillary canine teeth) of middle-aged cats. Eosin-
(see Chapter 76). Radiotherapy plus hyperthermia has been ophilic plaque usually occurs on the skin of the medial thighs
successful in some dogs with oral fibrosarcoma. In all cases, and abdomen. Linear granuloma is typically found on the
an oncologist should be consulted. posterior aspect of the rear legs of young cats but may also
Papillomatosis usually resolves spontaneously, although it occur on the tongue, palate, and oral mucosa. Severe oral
may be necessary to resect some of the masses if they inter- involvement of an eosinophilic ulcer or plaque typically pro-
fere with eating. Rarely there may be malignant transforma- duces dysphagia, halitosis, and/or anorexia. Eosinophilic
tion to squamous cell carcinoma. Fibromatous epulides may granuloma may affect the chin and paw pads in addition to
be resected if they cause problems. the mouth.

NEOPLASMS OF THE ORAL CAVITY Diagnosis
IN CATS An ulcerated mass may be found at the base of the tongue
or on the hard palate, the glossopalatine arches, or anywhere
Etiology else in the mouth. A deep biopsy specimen of the mass is
Tumors of the oral cavity are less common in cats than necessary for accurate diagnosis. Peripheral eosinophilia is
in dogs, but they are almost all malignant and are usually inconsistently present.
squamous cell carcinomas that are diagnosed and treated as
described for dogs. Cats are different from dogs in that they Treatment
also have sublingual squamous cell carcinomas and eosino- Systemic antibiotics directed against Staphylococcus spp.
philic granulomas (which mimic carcinoma but have a much (e.g., amoxicillin plus clavulanic acid, trimethoprim-sulfa
better prognosis). combinations) are often effective in treating indolent