Clinical and computed tomography findings in cats with nasopharyngeal stenosis.

OBJECTIVES: Concurrent anomalies are often found in nasopharyngeal stenosis and choanal atresia; some seem to be of primary nature, whereas others may be coincidental. This study aimed to report the computed tomography features and related comorbidities of these diseases. MATERIALS AND METHODS: A cross-sectional retrospective study was performed using case and control groups defined according to the presence of signs of upper airway disease and the presence/absence of nasopharyngeal stenosis, respectively. The inclusion criteria were full-head tomography scans and access to clinical records. The exclusion criteria were brachycephalic breed, head trauma and neoplasm. Clinical and computed tomographic findings and relevant comorbidities were recorded. RESULTS: Forty-three cats were included, 23 cases and 20 controls. The case group was significantly younger, had more paranasal sinus anomalies and never had turbinate lysis, also, had significantly more soft palate anomalies, which was significantly shorter. Nasopharyngeal stenosis varied from membrane appearance to partial or complete adhesion of the soft palate to the nasopharynx, was mainly located in the caudal region of the nasopharynx and was imperforated in approximately half of the cases. Imperforated membranes were significantly thicker in the sagittal plane and were significantly associated with nasal obstruction and soft tissue attenuation of the tympanic bulla. Hiatal hernia and ventricular asymmetry were only encountered in three and two cases, respectively, with nasopharyngeal stenosis. CLINICAL SIGNIFICANCE: Computed tomography in cats with nasopharyngeal stenosis can identify concurrent anomalies, can help to differentiate a possible choanal atresia and evaluate the magnitude of its significance.

Diagnosis, treatment and outcome of pheochromocytoma in a cat.

Pheochromocytoma in cats is a rare clinical condition characterised by the development of a secretory endocrine tumour that arises from the adrenal medulla. An 8-year-old castrated male, domestic shorthair cat was referred for further investigation of a 4-month history of progressive weight loss with normal appetite, polyuria/polydipsia, generalised weakness, and severe hypertension. Sonography and computed tomography of the abdomen disclosed a mass arising from the left adrenal gland. The contralateral adrenal gland was normal in size and shape. Results from a low dose dexamethasone suppression test and measurements of plasma aldosterone concentration and plasma renin activity ruled out a cortisol-secreting tumour and aldosteronoma. The clinical presentation made a sex-steroid secreting tumour unlikely. Increased plasma metanephrine and normetanephrine concentrations prioritised the differential diagnosis of pheochromocytoma. The cat underwent adrenalectomy of the left gland and histopathological diagnosis with immunohistochemical markers confirmed the diagnosis.

PCNA and grade in 13 canine oral squamous cell carcinomas: association with prognosis.

This study evaluated the prognosis factors of age, tumour size, anatomic location, histological grade and proliferating cell nuclear antigen (PCNA) expression in 13 dogs with oral squamous cell carcinoma (OSCC) with bone invasion and without signs of lymph node or distant metastasis. All animals were treated with radical excision performed with at least 1 cm margin, based on computed tomography images. In the 2-year follow-up, median disease-free survival was 138 days for dogs with grade 3 tumours and was not reached for those with grade 2 tumours. Grade 3 tumours and PCNA labelling index ≥65% were related with a shorter disease-free survival time and consequently poor prognosis (p = 0.003 and p = 0.034, respectively). Mean PCNA labelling index was significantly higher in recurrent cases (p = 0.011). Histological grade and PCNA expression may be important prognosis factors in canine OSCC.

p63 and E-cadherin Expression in Canine Oral Squamous Cell Carcinoma.

The expression of p63 and E-cadherin was studied in 22 oral squamous cell carcinomas in the dog according to immunohistochemical techniques. The association between these markers and clinicopathologic parameters was assessed. All tumor cells studied showed enhanced p63 expression. Regarding E-cadherin expression, 17 of 22 cases (77.3%) showed decreased immunoreactivity, and in 13 of 22 cases (59.1%), its expression was cytoplasmic. Neither p63 nor E-cadherin expression patterns were associated with tumor size, bone invasion, or lymph node metastasis. p63 score was related to proliferating cell nuclear antigen proliferative index (P = .020). A statistically significant correlation between the expression patterns of these 2 markers was noted (P = .026). Furthermore, they were related with tumor grade. An atypical p63 labeling and a cytoplasmic E-cadherin staining were statistically related with a higher tumor grade (P = .022 and P = .017, respectively). These findings suggest that changes in p63 and E-cadherin expression are frequent events in oral squamous cell carcinoma in dogs.

Neoadjuvant chemoradiotherapy and surgery as treatment for oral maxillary squamous cell carcinoma in a dog.

A gingival maxillary squamous cell carcinoma was diagnosed in a 12-year-old male Yorkshire Terrier. After a complete diagnostic work-up, including a computed tomography scan, the tumour was staged as T3bN1aM0 and considered non-resectable at presentation. The combination of neoadjuvant megavoltage radiotherapy and neoadjuvant and adjuvant chemotherapy with carboplatin and doxorubicin decreased the size of the tumour, allowing for surgery. The dog was free from local disease for 421 days after which it was euthanased at the owners' request.

Ectopic cervical thymic carcinoma in a dog.

A 10-year-old male German shepherd dog was referred for evaluation of a cranial cervical mass causing progressively worsening respiratory distress. A fine-needle aspirate of the mass was obtained and the cytology results were compatible with a carcinoma. The dog underwent chemotherapy without clinical improvement and was ultimately euthanased because of clinical deterioration. At post-mortem examination, an irregular multi-lobated mass in the cranial cervical region was observed causing ventro-lateral tracheal deviation. Histopathology and immunohistochemistry revealed a mixed population of CD3 lymphocytes and macrophages in an exuberant fibrous stroma, associated with dispersed cytokeratin-positive epithelial cells with marked eosinophilic cytoplasm. Some of the epithelial cells were arranged in concentric clusters that were interpreted as Hassall's corpuscles. Histopathological examination of the thyroid gland revealed several neoplastic emboli composed of epithelial cells similar to those observed in the cervical mass. To the authors' knowledge, this is the first report of an ectopic cervical thymic carcinoma in a dog.