Transnasal, Endoscopically Guided Skull-Based Surgery by Pharyngotomy for Mass Removal from the Sphenopalatine Sinus in a Horse.

OBJECTIVE: To report a transnasal, endoscopically guided ventral surgical approach for accessing the cranial and caudal segments of the sphenopalatine sinus for mass removal in a horse. STUDY DESIGN: Case report. ANIMAL: Adult horse with acute onset blindness referable to a soft tissue mass within the sphenopalatine sinus. CLINICAL REPORT: A 7-year-old Warmblood gelding presented with a history of running into a fence and falling. No neurologic signs were identified at initial examination but acute blindness was noted 3 weeks later. On computed tomography (CT) the sphenopalatine sinus was filled with a large homogeneous mass with poor contrast enhancement that extended dorsally with thinning to the dorsal cortex of the sphenoid bone, just rostral to the entrance of the optic canals into the cranial cavity. Surgical access to the sphenopalatine sinus was achieved using a transnasal, endoscopically guided ventral pharyngotomy approach and the mass lesion was removed. A presumptive diagnosis of chondroma was made based on histopathology. The horse recovered well from surgery, and although it has not regained vision as of 6.5 years postoperatively, the disease has not progressed. CONCLUSION: Transnasal, endoscopically-guided ventral surgical access to the sphenopalatine sinus is possible in horses and may improve access in horses with disease extending caudally beyond the palatine portion of the sinus. Use of smaller diameter or specialized instruments, such as various endoscopic bone cutting instruments, and CT image guidance may improve sinus access by this route.

Cartilaginous Tumors of the Larynx and Trachea in the Dog: Literature Review and 10 Additional Cases (1995-2014).

Cartilaginous tumors of the larynx and trachea are uncommon in the dog. The authors describe 10 cases diagnosed between 1995 and 2014 and review 16 cases in the literature. Seven of our cases were tracheal and 3 were laryngeal. Two of the laryngeal tumors were chondromas, which have not been previously reported in this site. The third laryngeal tumor was a myxochondroma. Of the 7 tracheal tumors, 6 arose from the ventral tracheal wall, including 2 that were extraluminal. Tracheal tumor types included chondrosarcoma (n = 3), chondroma (n = 2), and osteochondroma (n = 2). All of the laryngeal tumors and 5 of 7 of the tracheal tumors occurred in adult dogs (aged 5-11 years). The 2 tracheal osteochondromas were in young dogs (3-4 months) and were intrathoracic, while the remaining tracheal tumors were cervical. Surgical excision had a good outcome in most cases. Combining our 10 cases with the 16 previously reported cases showed that 6 (27%) of the affected dogs were Arctic breeds (Alaskan Malamute or Siberian Husky) suggesting a predisposition in this type of dog.

First occurrence of periosteal chondroma (juxtacortical chondroma) in Uromastyxmaliensis (Reptilia: Sauria: Agamidae).

The occurrence of a periosteal chondroma (juxtacortical chondroma) in an adult male Uromastyx maliensis is documented for the first time. The chondroma developed near the right shoulder joint from the periosteal membrane, causing partial atrophy in the surrounding skeletal muscles. In the chondroma tissues widespread central necrosis and secondary calcium salt deposition were observed. Monomorphic chondrocytes were irregularly spread in the chondromucin matrix. The lizard had locomotor problems due to irritation of the periosteum and reduced movement of the bones constituting the shoulder joint caused by the chondroma.

Lingual Chondrolipoma in a Dog.

A 13-year-old female Yorkshire terrier was presented with difficulty swallowing because of a lingual mass, which had grown to a size of 0.8 × 0.8 × 0.8 cm in 1 month. Grossly, the mass was located in the lingual frenulum and the cut surface was grey-white in colour. Microscopically, the mass was unencapsulated and composed of lobules of mature adipose tissue and cartilaginous tissue with abundant basophilic myxoid matrix separated by fibrous connective tissue. Immunohistochemically, almost all of these cells were positive for vimentin and S100. Chondroid cells and their adjacent spindle cells were also positive for SOX9. Based on these findings, a diagnosis of chondrolipoma was made. To the best of our knowledge, this is the first report of a chondrolipoma originating as a primary tumour in the lingual frenulum of a dog.

Aortic chondroid neoplasia in two Labrador Retriever dogs.

In the same week, two Labrador Retriever dogs presented to The Ohio State University Veterinary Medical Center for cardiac evaluation. The presenting signs in both dogs included: weight loss, weakness, lethargy, and decreased femoral pulses. The first dog presented in cardiogenic shock and biventricular congestive heart failure, which initially responded to treatment; however, the dog was euthanized due to deteriorating clinical condition. In contrast, the second dog had a milder clinical course without signs of congestive heart failure, and remained stable over the 2-month period of clinical evaluation prior to euthanasia. Echocardiographic evaluation revealed a dilated cardiomyopathy phenotype in the first dog, while a space-occupying intraluminal mass originating at the aortic valve with preserved left ventricular systolic function was observed in the second dog. At autopsy, each dog had a large obstructive luminal mass affecting the ascending aorta and arch. Histopathology revealed that the mass in the first dog was consistent with a benign chondroma, while in the second dog the morphologic characteristics, mitotic activity, and infiltrative growth justified a diagnosis of chondrosarcoma. This report presents the contrasting clinical disease progression and findings in two dogs with aortic neoplasia, with a proposed pathogenesis of cardiac failure secondary to aortic neoplasia.

Spontaneous pulmonary neoplasms in cynomolgus monkeys (Macaca fascicularis)--a report of two cases.

The first lung tumour-bearing animal was a 7 years and 3 months old cynomolgus monkey. Microscopic examination revealed a neoplastic mass under the pleura that consisted of squamous islands with little keratinization, multifocal mineralization of the keratin, inflammatory cell and foreign body-type giant cell infiltration. It was classified as pulmonary squamous cell carcinoma. In a second cynomolgus monkey (2 years and 10 months old) a lung mass was observed at necropsy. Microscopically the tumour consisted of numerous islands of cartilage with glandular structures lined by a cuboidal epithelium between them. The neoplasm was classified as cartilaginous hamartoma.

Differentiation between chondroma and squamous cell carcinoma: evaluation of subtraction image of MRI.

The image processing procedure has become widely applied as a visual aid in imaging diagnosis. The subtraction image of MRI obtained by digitally subtracting an unenhanced image from a contrast-enhanced image, depicted a discrete distribution of the contrast agent. Subtraction images in the clinical cases were compared. The subtraction image in a case of chondroma demonstrated a relatively uniform distribution of a contrast agent, with a well delineated neoplastic lesion. The subtraction image in a case of squamous cell carcinoma, the contrast agent was distributed heterogeneously in the carcinoma and well permeated into the muscle. Different patterns of subtraction image were obtained in the clinical cases of chondroma and squamous cell carcinoma in this study. The findings suggest the potential usefulness of the subtraction image for diagnosing the degree of malignancy.

Chondroma of the foreleg in a Syrian hamster.

A spontaneous bone tumour in the foreleg of a Syrian hamster was shown to be a chondroma; this is only the second report of such a tumour and the first described in detail.

Tumours of the bone in C57BL/10J mice.

Tumours of the bone were found in 17 (12 females and 5 males) of 6768 (0.25%) C57BL/10J mice (3384 males and 3384 females) pooled from 14 oncogenic studies carried out from 1973 to 1987. Tumours of bone were found predominantly in female mice and were age related. The tumours were classified histologically as osteosarcoma (5 osteoblastic, 6 mixed type and 1 fibroblastic), chondroma (2), chondromyxoid fibroma (1), chondrosarcoma (1) and periosteal fibroma (1).

Cranial osteochondroma in a white-tailed deer (Odocoileus virginianus).

A large osteochondroma of the skull was diagnosed in a young adult free-ranging white-tailed deer (Odocoileus virginianus) from Wyoming. The 4.8-kg neoplasm primarily involved the left frontal bone with extension into the cranial cavity. Microscopically, the neoplasm was composed of well differentiated trabecular bone and islands of cartilage. This neoplasm is rare in domestic species and has not been reported in cervids. Though benign in morphology, the location and size of the neoplasm was probably responsible for debilitation of the deer.

Thoracic vertebral osteochondroma in a cat.

A thoracic vertebral (T5) osteochondroma was discovered in a 1 1/2-year-old male blue Persian cat with a history of acute hind limb paresis. Myelography revealed a mass on the dorsal surface of the vertebral body, which resulted in dorsal compression of the spinal cord. A dorsal laminectomy was performed, and the mass was rongeured entirely from the vertebral body. Although the cat's progress was initially slow after surgery, its neurologic status was assessed to be near normal, 15 months later.

Chondrosarcoma arising in a multilobular chondroma in a cat.

A large mass firmly attached to bone was found on the skull in an adult, male cat. A diagnosis of chondrosarcoma arising in a multilobular chondroma was made from a biopsy specimen and confirmed at necropsy.

Orbital chondroma rodens in a dog.

A chondroma rodens involving the superficial medial aspect of the right orbit was diagnosed in a 9-year-old dog referred because of chronic unilateral epiphora. Examination revealed several ophthalmic abnormalities attributable to a space-occupying mass in the superficial medial aspect of the orbit. The mass was excised; however, regrowths at the primary site necessitated additional surgical interventions. The dog was given radiation therapy, which provided encouraging results. Subtle histologic differences as well as differing epidemiologic features suggest that chondroma rodens is not analogous to the human entity of juvenile aponeurotic fibroma, to which it has been compared in the past.

Enchondroma in a rhesus monkey.

A 2.5-year-old rhesus monkey was examined because of a bony enlargement of the distal portion of the right tibia. On the basis of radiographic and histologic findings, enchondroma was diagnosed. The tumor enlarged over the next 2 years, but the monkey continued to have normal use of its limb.

Tracheal resection and anastomosis for an intratracheal chondroma in a ball python.

A 9-year-old female ball python was evaluated for lethargy and respiratory compromise. Radiographic and endoscopic examination revealed a 1-cm intratracheal mass occluding the tracheal lumen. A partial tracheal resection and anastomosis was performed to remove the mass. On histologic examination, the mass was determined to be an intratracheal chondroma. Eosinophilic cytoplasmic inclusions observed within the tissue were calcium deposits. Electron microscopy was used to differentiate these from viral inclusion bodies often associated with neoplasms in reptiles. Endoscopic evaluation of the trachea 5 weeks after surgery revealed complete healing and minimal stenosis at the surgery site. Indications of tumor regrowth were not evident. Clinical signs of recurrence of respiratory compromise had not been observed 9 months after surgery.

Tracheal osteochondroma in a dog.

A young female Labrador Retriever-type dog had a 4 1/2-month history of respiratory distress, which eventually became severe, leading to cyanosis. Physical examination suggested an upper airway obstructive lesion, which was confirmed by bronchoscopy and radiography to be a mass in the thoracic portion of the trachea. The mass was removed surgically and, on histologic examination, was found to be an osteochondroma. Six months after surgical extirpation, there was no indication of recurrence of tumor.

Spinal cord compression caused by osteocartilaginous exostoses of the spine in two dogs.

Two dogs, one 4 months old and the other 1 year old, had histories of progressive posterior weakness. In both cases, there was severe asymmetric proprioceptive loss but appreciable preservation of strength. Benign, cystic expansile lesions involving the facets and lamina of the thoracic spine were observed radiographically; a single lesioons was demonstrated in the other. Examination of biopsy speciments taken at the time of laminectomy revealed the lesions to be osteocartilaginous exostoses (osteochondromas, ecchondromas, exostoses). The progress of dogs 1 and 2 has been monitored for 1 1/2 years and 9 months, respectively. Dog 1 has no weakness or proprioceptive loss; dog 2 has a mild proprioceptive loss in the right hindlimb.

Solitary osteochondroma of the radius in three horses.

Osteochondroma of the distal portion of the radius was diagnosed in 3 horses with a history of lameness and distention of the common tendon sheath of the superficial and deep digital flexor tendons at the level of the carpal canal. In 2 horses, the exostosis was removed through an incision at the caudal border of the lateral digital extensor muscle above the carpal ligament.

Synovial chondrometaplasia in five dogs.

Synovial chondrometaplasia was diagnosed in 5 dogs. Four dogs improved dramatically after surgical removal of subsynovial nodules, but the fifth improved only slightly. This potentially treatable condition is recognized in human beings, and has been described in dogs in the German scientific literature. Synovial chondrometaplasia should be suspected if numerous joint mice are visualized radiographically, without an obvious inciting cause. It also should be suspected when periarticular osteophytes are found radiographically in unusual locations.

Orbital neoplasms in cats: 21 cases (1974-1990).

Squamous cell carcinoma was the most common neoplasm found in a review of case records of 21 cats with histopathologically confirmed orbital neoplasms. Other neoplasms found were lymphosarcoma, undifferentiated carcinoma, malignant melanoma, adenocarcinoma, fibrosarcoma, chondroma, and hemangiosarcoma. Three (14%) neoplasms were primary, 15 (71%) were secondary, invading the orbit from adjacent tissues, and 3 (14%) were a manifestation of multicentric disease. The most common clinical sign was exophthalmia, followed by chronic epiphora, enophthalmia, and strabismus. Mean survival time after diagnosis was 1.9 months. Ten cats were euthanatized at the time of diagnosis because of extensive disease. Mean survival time of the other 11 cats was 4.3 months. Skull radiography was helpful in diagnosing orbital neoplasms in 8 of 11 cats that had invasion of the orbit by adjacent neoplasms.