Radiation therapy for long-term control of odontogenic tumours and epulis in three cats

Maxillary and Mandibular Peripheral Odontogenic Fibromas (Fibromatous Epulides of Periodontal Ligament Origin) in a Cat

Peripheral odontogenic fibroma (POF) is an uncommon finding in the mouth of cats. Few cases have been reported in the literature. The present report describes an adolescent, male-castrated domestic shorthair cat with POFs at the rostral upper and lower jaws that were treated via marginal excision including removal of underlying bone. Despite the high incidence of recurrence reported in the literature, recheck examinations up to 11 months postoperatively did not show regrowth of the gingival masses. Thus, marginal excision including removal of underlying bone appears to be a viable treatment option for POF in cats.

A Clinicopathological Study of 52 Feline Epulides

A retrospective study was performed to characterize 52 new cases of feline epulides between 1995 and 2001, with clinical and pathological results classified according to Head's histopathologic criteria for canine epulides. The incidence of the fibromatous, acanthomatous, ossifying, and giant cell epulis were respectively 57.7% (30/52), 7.7% (4/52), 5.8% (3/52), and 28.8% (15/52). Giant cell epulides presented significant differences in clinical behavior compared with the fibromatous type, including rapid growth ( P < .0001), presence of ulcerative changes ( P < .01), and rapid recurrence after surgery ( P < .01) from which euthanasia was judged necessary in 4 cases. Fifteen giant cell epulides were additionally examined in order to characterize the lesion both histochemically and immunohistochemically and to investigate the origin of the multinucleated giant cells (MGCs). Van Gieson staining showed osteoid and woven bone formation in 11 cases. Both the MGCs and a fraction of the mononuclear cells were positive for vimentin, tartrate-resistant acid phosphatase (TRAP), a commonly accepted marker for osteoclasts, and the polyclonal antibody receptor activator of nuclear factor κβ (RANK), a cytokine leading to the differentiation of osteoclast progenitors into mature osteoclasts in presence of its ligand. MGCs were negative for smooth muscle actin, MIB-1, and factor VIII. The giant cell epulis may be a variant of the fibromatous and ossifying epulis in which extensive ulceration and inflammation results in increased osteoclastic activity. The osteoclast-like giant cells are most likely formed from a monocyte/ macrophage-like osteoclast precursor that differentiates into osteoclasts under the influence of mononuclear osteoblast-like stromal cells.

Benign cementoblastoma (true cementoma) in a cat

Case summary

A 10-year-old castrated male domestic shorthair cat was presented for assessment of a gingival mass surrounding the left maxillary third and fourth premolar teeth. The mass was surgically removed by means of a marginal rim excision, and the tissue was submitted for histological assessment. It was identified as a benign cementoblastoma (true cementoma). There was proliferation of mineralized eosinophilic material with multiple irregularly placed lacunae and reversal lines, reminiscent of cementum. The cat recovered uneventfully from the anesthesia, and there was no evidence of tumor recurrence 6 months after surgery.

Relevance and novel information

Cementoblastomas (true cementomas) in domestic animals are rare, with just a few reports in ruminants, monogastric herbivores and rodents. Cementoblastoma is considered a benign tumor that arises from the tooth root. The slow, expansive and constant growth that characterizes these masses may be accompanied by signs of oral discomfort and dysphagia. This case report is intended to increase knowledge regarding this tumor in cats and also highlights the importance of complete excision of the neoplasm. To our knowledge, there are no previous reports in the literature of cementoblastoma in the cat.

Treatment choices for oral cancer in cats. What is possible? What is reasonable?

Practical relevance Oral cancers are not the most common tumour in our domestic cats, but the death rate associated with cancer in this location is particularly high. This is largely because the cancer is discovered late in its development and also because of the severe debility it causes when the patient is unable or unwilling to eat and drink.

Audience This review of malignant oral tumours (squamous cell carcinoma, oral sarcoma, oral melanoma and salivary adenocarcinoma) and benign oral tumours that may mimic malignant lesions is directed at all veterinarians that see older cats - both for ‘health and wellness’ as well as for more advanced treatment of already diagnosed neoplasia.

Patient group As it is almost always older cats that are affected, patients will have a strong bond with their owners. These cats also often have unrelated intercurrent disease that may affect treatment choices, the way treatment is administered, and whether the owner chooses aggressive or palliative therapy.

Evidence base While the literature on treatment of oral cancer in dogs is well established, until recently it was less so in cats. As researchers focus on treating cats with curative intent, as well as palliatively and supportively, the material available to guide veterinarians has also increased. This article evaluates the current literature from the author's perspective as an oncologist and a cat owner.