A Combined Ventral Extraoral and Intraoral Approach for Mandibulectomy in 9 Cats: A Case Series

This retrospective case series describes a combined ventral extraoral and intraoral approach for mandibulectomy in cats and highlights the importance of prompt management of the postoperative iatrogenic malocclusion through dental extraction, crown height reduction with vital pulp therapy or root canal therapy of the contralateral mandibular canine tooth. Nine cats were reviewed for signalment, history and physical examination, diagnostic workup, tumor type, mandibulectomy extension, lymph node removal as well as both intraoperative and postoperative complications. The performed surgical procedure was a combination of an extraoral approach ventrally to the mandible and an intraoral approach to remove the whole or a part of the mandible. Lymphadenectomy was achieved using the same surgical access. None of the cats had intraoperative complications. Postoperative complications were limited to regional swelling and drooling lasting a week. Seven cats were able to eat immediately after the surgery. Of the other 2 cats, 1 regained the ability to eat within a month and 1 only ate from the owner's hands. The surgical approach for mandibulectomy described allowed better access and visualization of the caudal part of the mandible and direct access to regional lymph nodes. Moreover, if the expected postoperative malocclusion is managed during the same surgical procedure, there is a higher rate of postoperative eating ability compared to what is reported in the literature.

Intra-articular osteoma in the stifle joint of a cat

Case summary

A 13-year-old male castrated cat was referred to our clinic for a 2-month history of right hindlimb lameness. Radiographs and CT showed a solid bony mass within the stifle joint. The mass was resected by arthrotomy and osteotomy of the tibial tuberosity. Histopathological examination revealed the diagnosis of osteoma. Recovery from surgery was uneventful. At the 8-week follow-up examination, the cat was free of clinical signs.

Relevance and novel information

Feline osteomas are rare; only few cases have been reported. To the best of our knowledge, this is the first report of an intra-articular osteoma in the stifle joint of a cat and description of its surgical resection.

Mandibular osteoma in a Haflinger mare: clinical and pathological features

A 11-year-old, Haflinger breed mare developed a slowly growing mass, protruding on the ventral aspect of the mandible. On palpation, the lesion was pedunculated, very firm, cold and not painful. Radiographic examinations showed a radiopaque, multi-lobular, "mushroom-like" lesion, which arose from the mandibular cortex without involving the bone marrow cavity. Thereafter, the mass was excised for cosmetic purposes. Microscopically, the lesion mainly consisted of bone trabeculae, covered by a thick layer of connective tissue resembling the periosteum. History and clinical findings allowed the temptative diagnosis of mandibular osteoma, which was further supported by diagnostic imaging and pathological features. In particular, the presence of pedunculated lesions arising from the bone surface appeared as highly suggestive of osteoma. Equine osteomas usually affect paranasal sinuses and the rostral mandible and share many similarities with other neoplastic and neoplastic-like conditions, such as ossifying fibroma and fibrous dysplasia. The prognosis is good whenever the neoplasm is fully removed, that depending on the localization and the size of the mass.

A Holistic Approach to Bone Tumors in Dogs and Cats: Radiographic and Histologic Correlation

The skeletal system is a common site for neoplasia in dogs and cats, and primary bone tumors may develop from any of the mesenchymal tissues present in bone. Imaging and histopathology are routinely used in the diagnosis of bone tumors, and the 2 techniques are highly complementary. While imaging may be highly suggestive of a specific diagnosis and treatment may be instituted based on this, definitive diagnosis requires histopathology of either incisional or excisional biopsies or an amputation specimen. However, there are a number of diagnostic dilemmas when the pathologist interprets bone biopsy samples, such as distinguishing reactive bone and tumor bone, fracture callus and tumor bone, different benign fibro-osseous lesions, and different types of bone sarcoma. This review outlines the characteristic radiographic and histologic changes associated with these diagnostic problems to aid in resolving them. When a holistic approach is taken to evaluation of the signalment, history, and clinical, radiologic, and microscopic features, a diagnosis may be possible. The pathologist is greatly assisted in the interpretation of bone samples by having access to imaging and should routinely request either the images or the imaging reports if they are not received from submitting veterinarians.

Successful subtotal orbitectomy in a cat with osteoma

Case summary

A 14-year-old Siamese neutered male cat was evaluated for anorexia and a left periorbital mass. Skull radiographic findings showed a well-defined lesion resembling new compact bone formation without destruction. A subtotal orbitectomy was indicated. The tumor was removed intact with a normal tissue margin of at least 1 cm. There were no postsurgical complications. Histopathologic examination revealed an osteoma. The cat returned to normal appetite and activity 15 days after surgery. Six months after surgery, there were no gross signs of recurrence.

Relevance and novel information

Periorbital tumors are infrequently diagnosed in companion animals and most are malignant. In this case, the diagnosis was orbital osteoma. The most commonly affected bone for osteoma in cats is the mandibular bone; few cases have been identified in orbital bones. Orbital surgery has the potential to be challenging owing to complex anatomy, difficult exposure and the tendency to bleed. Surgical complications are common. In this case, although the disease was advanced, subtotal orbitectomy was successfully performed.

Benign and Malignant Proliferative Fibro-osseous and Osseous Lesions of the Oral Cavity of Dogs

Ossifying fibroma (OF) and fibrous dysplasia (FD) are benign, intraosseous, proliferative fibro-osseous lesions (PFOLs) characterized by replacement of normal bone by a fibrous matrix with various degrees of mineralization and ossification. Osteomas are benign tumors composed of mature, well-differentiated bone. Clinical, imaging, and histologic features of 15 initially diagnosed benign PFOLs and osteomas of the canine oral cavity were evaluated. Final diagnoses after reevaluation were as follows: OF (3 cases), FD (4 cases), low-grade osteosarcoma (LG-OSA) (3 cases), and osteoma (5 cases). Histology alone often did not result in a definitive diagnosis for PFOL. OF appeared as a well-circumscribed, radiopaque mass with some degree of bone lysis on imaging. Most lesions of FD showed soft tissue opacity with bone lysis and ill-defined margins. Low-grade OSA appeared as a lytic lesion with a mixed opacity and ill-defined margins. Osteomas were characterized by a mineralized, expansile, well-circumscribed lesion. Although histologic features of PFOLs were typically bland, the lesions diagnosed as LG-OSA had some features of malignancy (eg, bone invasion or a higher mitotic index). Treatment varied widely. Of the 10 dogs with benign PFOL or osteoma with known outcome (10/12), 9 showed either complete response (6/10) or stable disease (3/10) after treatment. Of the 2 dogs with LG-OSA with known outcome, 1 showed complete response after curative intent surgery, but 1 patient had recurrence after partial maxillectomy. Definitive diagnosis of mandibular/maxillary PFOL is challenging via histopathologic examination alone, and accurate diagnosis is best achieved through assimilation of clinical, imaging, and histopathologic features.

Clinical feline dental radiography

Dental radiography is a necessary diagnostic modality in small animal practice. It is not possible to accurately assess and diagnose tooth resorption, periodontal disease, endodontic disease, neoplasia and injury without it. Dental radiography is also necessary for treatment and assessment of the patient postoperatively.