Variation in the MRI appearance of the canine pituitary gland.

A recent publication described pathological findings in the pituitary gland incidentally discovered during routine necropsies of the brain of dogs and cats; however, imaging characteristics of these lesions were not reported. Aims of this retrospective, observational study were to characterize MRI variants and incidental lesions in pituitary glands of dogs with no clinical signs of pituitary disease. Cranial MRIs from dogs with no suspicion of pituitary disease, based on history and presenting clinical signs, were retrieved from a veterinary teleradiology database during the period of January 2014 to January 2016. Images were reinterpreted by two observers and pituitary lesions were described based on consensus. A total of 580 scans were evaluated and pituitary lesions were detected in 78 dogs (13.44%). Pituitary cystic lesions were the most common finding and occurred in 31 dogs (5.34%). Of these 31 dogs, the majority (74%) were of toy or brachycephalic breed. Partial or total empty sella lesions were detected in 14 dogs (2.41%), and all of these were small or toy breeds. A significantly increased incidence of the partial empty sella lesion was found in male dogs (P = .034). Pituitary lesions greater than 1 cm occurred rarely (0.69%). There was a significant association between low-field (LF) MRI strength and detection of a partial or total empty sella lesion (P = .0112), and detection of a pituitary lesion greater than 1 cm (P = .0125). A significant difference was present between the MRI field strength (FS) that identified pituitary cysts and the FS that detected an empty sella (P = .0068), with the former being a high FS and the latter a LF strength. The findings from this study indicated that up to 13% of dogs with no presenting clinical signs of pituitary disease may have MRI pituitary lesions.

Factors influencing wound healing complications after wide excision of injection site sarcomas of the trunk of cats.

OBJECTIVE: Wide surgery is the mainstay of the multimodal treatment of injection site sarcomas (ISS) in cats. The aim of the study was to analyze potential factors influencing the development of wound healing complications (WHC) in cats undergoing wide excision of ISS. STUDY DESIGN: Retrospective case series. ANIMALS: Forty-nine cats with ISS located on the trunk underwent wide excision after contrast-enhanced computed tomography planning. METHODS: The prognostic effect of covariates (sex, age, weight, body condition score (BCS), site, clinical dimension (CD), computed tomographic dimension (CTD), histotype, duration of surgery, surgical margin status, local anesthesia) on total, major and minor WHC was evaluated by univariate and bivariate analysis. Cox model was used for total WHC and Fine and Gray model was used for major and minor WHC. The relationship between duration of surgery and clinical and imaging variables was evaluated. RESULTS: The main factor associated to the risk of total and major WHC was surgical time. Based on univariate analysis, pattern of reconstruction, CDT, CD, weight, and BCS were significant prognostic factors for major WHC, but this was not confirmed when adjusted for other clinical variables in bivariate analysis. The duration of surgery was influenced by excision pattern and tumor CTD width. CONCLUSIONS: An increased duration of surgery as the consequence of complex surgical procedures represented the best predictor for the development of WHC.

Middle ear cholesteatoma in 11 dogs.

Middle ear cholesteatoma is a rare condition in dogs with chronic otitis. Otorrhea, otodinia, and pain on temporomandibular joint palpation are the most common clinical signs. Neurological abnormalities are often detectable. Computed tomography reveals the presence of an expansive and invasive unvascularized lesion involving the tympanic cavity and the bulla, with little or no contrast enhancement after administration of contrast mediu. Video-otoscopy may detect pearly growth or white/yellowish scales in the middle ear cavity. Surgery is the only therapy but is associated with a high risk of recurrence.

Bilateral orbital and nasal aspergillosis in a cat.

A 12-year-old, 4 kg, castrated male Persian cat was referred with a 2-month history of sneezing and bilateral mucopurulent nasal discharge. Rhinoscopically acquired nasal biopsies at this time revealed bilateral lymphoplasmacytic rhinitis. A tapering dose of oral prednisone caused the complete remission of the clinical signs, but 2 months after discontinuation of the therapy, the rhinitis recurred and the OD became exophthalmic. Computed tomography showed a soft tissue mass in both sides of the nasal cavity, both frontal sinuses, the right orbit, and to a lesser extent the left orbit. A fine needle aspirate of the right orbit revealed pyogranulomatous inflammation and Aspergillus spp. hyphae. Repeat nasal biopsy demonstrated multi-focal necrosis and a mixed inflammatory cell process which now included macrophages and scattered septate fungal hyphae. A few days later the cat became bilaterally blind and a contrast enhancing lesion involving the optic chiasm was found on magnetic resonance imaging. Despite a poor prognosis, therapy consisted of exenteration of the right orbit and trephination of both frontal sinuses before the planned initiation of medical antifungal therapy. Unfortunately, the cat died of cardiac arrest intraoperatively. Aspergillus fumigatus was cultured from both orbits at necropsy. Orbital aspergillosis has been rarely reported in cats and its relationship with lymphoplasmacytic rhinitis is unclear. In this patient lymphoplasmacytic rhinitis or previous antibiotic/corticosteroid therapy may have allowed secondary fungal invasion of the nasal mucosa and subsequently both orbits and the brain. Alternatively, Aspergillus infection may have preceded the lymphoplasmacytic rhinitis.

Meningeal carcinomatosis and spinal cord infiltration caused by a locally invasive pulmonary adenocarcinoma in a cat.

CASE SUMMARY: A 12-year-old domestic shorthair cat was presented with acute non-painful hindlimb proprioceptive ataxia localising to T3-L3 spinal cord segments. MRI revealed paravertebral muscular hyperintensity on T2-weighted images at the level of T7-T8 vertebrae. The cat improved on conservative management but deteriorated 3 months later. Repeated MRI showed meningeal enhancement at the same level and hyperintensity of the paravertebral musculature extending to the right thoracic wall and pleural space on short tau inversion recovery images. Thoracic CT showed mineralised lesions of the right lung, restricted pleural effusion and expansile bone lesions affecting multiple ribs. The cat had been treated for pyothorax 5 years earlier but manifested no current respiratory signs. Cerebrospinal fluid (CSF) examination showed lymphocytic pleocytosis but no neoplastic cells. Biopsy of the affected muscles and cytology of the lung and pleural lesions suggested a malignant epithelial cell tumour. Post-mortem examination confirmed a pulmonary adenocarcinoma locally infiltrating the thoracic wall, T7-T8 vertebrae and the spinal cord white matter. Meningeal carcinomatosis was detected with neoplastic cells invading the ventral median fissure of the spinal cord. No metastases were observed in other organs, indicating that neoplastic cells reached the spinal cord by direct extension. RELEVANCE AND NOVEL INFORMATION: Spinal meningeal carcinomatosis has not been reported in dogs or cats with extraneural tumours but is a well-recognised condition in humans. A metastatic cause of meningeal enhancement should be considered in patients with neurological signs of unknown origin. Imaging findings and CSF results can be non-specific.

Canine aural cholesteatoma: a histological and immunohistochemical study.

Canine aural cholesteatoma is an epidermoid cyst that forms in the middle ear cavity as a rare complication of otitis media but the aetiopathogenesis remains controversial. In the present study, 13 cases of canine aural cholesteatoma were investigated histologically and immunohistochemically and compared with cases of chronic otitis. The immunohistochemical investigation was performed using the following monoclonal antibodies: anti-cytokeratins (CK) 14, 16, 8/18, and 19, and anti-Ki67. The proliferative indexes (PIs) of cholesteatomata and otitis epithelium were calculated as the percentage of Ki67 positive nuclei/total nuclei. Histologically, the cholesteatomata were composed of a hyperplastic, hyperkeratotic epithelium (matrix) resting on a fibrous perimatrix, infiltrated by inflammatory cells and devoid of cutaneous adnexa. Immunohistochemically, the cholesteatoma epithelium was CK14- and CK16-positive, and CK8/18- and CK19-negative. A similar pattern of CK expression was found in otitis externa. In otitis media, ciliated epithelium stained CK8/18- and CK19-positive in all layers, CK14-positive in the basal layers, and CK16-negative. The mean PIs in cholesteatomata and otitides were 18.8 and 17.8, respectively. The immunohistochemical pattern of CK expression in cholesteatomata, when compared with chronic otitis, was suggestive of hyperproliferative epithelium, but its origin could not be demonstrated. Comparable PI values were obtained in cholesteatoma and in chronic otitis, which confirmed that Ki67 is a valuable indicator of a hyperproliferative state, but not a predictor of aggressiveness.

Computed tomography characteristics of fibrosarcoma -- a histological subtype of feline injection-site sarcoma.

Feline injection-site sarcoma (FISS) may be a consequence of subcutaneous injection. In the present study, the medical records and the computed tomography (CT) features of 22 cats with a FISS, histopathological subtype fibrosarcoma, were used. The majority of the fibrosarcomas (45%) were located in the interscapular region. All fibrosarcomas, except one with mild enhancement, showed strong contrast uptake, characterised as ring (42%), heterogeneous (36%), homogeneous (9%), heterogeneous/ring (6.5%) or mixed heterogeneous/homogeneous enhancement (6.5%). The longest axis of the mass was in a cranio-caudal (68%) or dorso-ventral (32%) direction. The median volume calculated on CT was 7.57 cm(3). Common features were a marked local invasiveness of the musculature and heterogeneity of the tissue in the periphery of the neoplasia. When the fibrosarcoma was interscapular, performing an additional post-contrast scan with the forelimbs positioned caudally along the body, in addition to the standard protocol with the forelimbs extended cranially, allowed better evaluation of the actual relationship between the tumour and the surrounding tissues. The mean number of muscles involved with the tumour was 2.09 with extended and 1.95 with flexed forelimbs. When a lower number of structures was considered infiltrated through the double positioning, a less invasive surgical approach to underlying muscles and scapula was performed.

Safety of contrast-enhanced ultrasonography in dogs and cats: 488 cases (2002-2011).

OBJECTIVE: To determine the incidence of adverse events within 24 hours after contrast-enhanced ultrasonography (CEUS) in dogs and cats and compare the risk of death within 24 hours after imaging for animals that underwent ultrasonography with and without injection of a contrast agent. DESIGN: Retrospective case-control study. ANIMALS: 750 animals (411 case dogs, 238 control dogs, 77 case cats, and 24 control cats). PROCEDURES: At 11 institutions, medical records were reviewed of dogs and cats that had CEUS performed (cases) as were medical records of dogs and cats with clinical signs similar to those of case animals that had ultrasonography performed without injection of a contrast agent (controls). Information regarding signalment; preexisting disease; type, dose, and administration route of contrast agent used; immediate (within 1 hour after CEUS) and delayed (> 1 and ≤ 24 hours after CEUS) adverse events; and occurrence and cause of death (when available) was extracted from each medical record. Risk of death within 24 hours after ultrasonography was compared between case and control animals. RESULTS: Of the 411 case dogs, 3 had immediate adverse events (vomiting or syncope) and 1 had a delayed adverse event (vomiting). No adverse events were recorded for case cats. Twenty-three of 357 (6.4%) clinically ill case animals and 14 of 262 (5.3%) clinically ill control animals died within 24 hours after ultrasonography; risk of death did not differ between cases and controls. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that CEUS was safe in dogs and cats.

Effect of glucocorticoid administration on adrenal gland size and sonographic appearance in beagle dogs.

Our aim was to evaluate the influence of glucocorticoids on the adrenal gland using ultrasonography. Eleven healthy beagles were used in a prospective placebo-controlled study. All dogs received hydrocortisone at 10 mg/kg twice a day per os for 4 months or a gelatin capsule twice a day per os as a placebo. Clinical and endocrinologic examination of the dogs and ultrasonographic evaluation of adrenal echogenicity, shape, and measurement of the length and height of the cranial and caudal pole were performed at baseline (TO), at 1 (T1) and 4 months (T4) after the beginning of treatment, and 2 months after the end of the treatment including 1 month of tapering and 1 month without treatment (T6). The dogs were assigned randomly to the glucocorticoid (n = 6) and placebo groups (n = 5). At T1, the difference between the two groups for the height of the cranial and caudal pole was not ultrasonographically remarkable despite a statistically significant difference (P = 0.0165 and P = 0.0206). Decreased height and length of entire gland were observed at T4 (P < 0.0001, P = 0.0015, and P = 0.0035, respectively). Percentages of atrophy were variable between dogs. Both adrenal glands regained normal size and shape 1 month after cessation of glucocorticoid administration. As not all dogs developed marked adrenal gland atrophy and the degree of atrophy varied widely between individuals, ultrasonography cannot be the technique of choice to detect iatrogenic hypercortisolism. Ultrasonographic changes are reversible within 1 month after the end of glucocorticoid administration.

Feline injection-site sarcoma: recurrence, tumour grading and surgical margin status evaluated using the three-dimensional histological technique.

The three-dimensional histology technique is used in human medicine for the evaluation of complete lateral and deep surgical margins. In this study, the technique was applied to 48 excised feline injection-site sarcoma specimens. The predictive value of the histological margin status and tumour grading on local recurrence was investigated. In 32/48 cases, the margins were non-infiltrated, whilst in the remaining 16 cases, they were infiltrated. Overall, 6/32 (19%) tumours with non-infiltrated margins and 11/16 (69%) with infiltrated margins recurred. Tumours with infiltrated margins recurred about 10 times more frequently compared to tumours with non-infiltrated margins (P=0.0011). No statistically significant correlation was observed between grading and recurrence. The assessment of margin status using the 3D histology technique showed a good predictivity for post-surgical tumour recurrence. Extensive application of the 3D histology technique is recommended to standardise the evaluation of histological margins and to allow comparison between results from different laboratories.

Computed tomography features of middle ear cholesteatoma in dogs.

We describe the computed tomography (CT) findings in 11 dogs with middle ear cholesteatoma. The cholesteatoma appeared as an expansile tympanic cavity mass with a mean attenuation value of 55.8 +/- 4.2 Hounsfield units. There was no appreciable contrast enhancement of the tympanic bulla contense but ring enhancement was seen in four dogs. Due to the slow progressive growth, the lesion causes severe bone changes at the contour of the tympanic bulla, including osteolysis, osteoproliferation and osteosclerosis, expansion of the tympanic cavity, and sclerosis or osteoproliferation of the ipsilateral temporomandibular joint and paracondylar process. Cholesteatoma can cause lysis of the petrosal part of the temporal bone, leading to intracranial complications. Although not definitive, CT provides useful information for distinguishing a middle ear cholesteatoma from otitis media and neoplasia. In otitis media, enlargement of the tympanic cavity is not routinely observed. In tumors that primarily affect the middle or inner ear, the predominant signs are lysis of the contour of the tympanic bulla or the petrosal part of the temporal bone, soft tissue swelling around the middle ear and marked contrast enhancement. In tumors that arise from the external ear, a soft tissue mass is visible within the external acusticus meatus, and the middle ear is only involved secondarily.