Oral and Sinonasal Tumors.

This article reviews the different types of equine non-neoplastic and neoplastic oral and sinonasal tumors and describes their known prevalence and general characteristics. The clinical and ancillary diagnostic findings (primarily radiography and endoscopy, and increasingly computed tomography) for each type of growth that can aid diagnosis are described. Most lesions require a histopathological confirmation of the diagnosed growth. The possible treatments and prognosis for these growths are briefly described.

Computed tomographic characteristics of frontal sinus ossifying fibroma in a dog.

A 10-year-old female spayed Kelpie cross was presented to The Austin Vet Specialists for further investigation of a mineralized, lobulated frontal sinus mass that had previously been detected radiographically. Computed tomography (CT) revealed a large, expansile, well-defined, heterogeneously mineral attenuating mass invading both frontal sinuses. The mass was surgically debulked via a frontal sinusotomy approach. Histopathology was consistent with ossifying fibroma. This  is the first published report to describe frontal sinus ossifying fibroma in a dog, and the second to describe CT features of ossifying fibroma involving the cranium in a dog.

Secondary extracranial paranasal sinus meningioma in a dog.

A 13-year-old Maltese dog was presented for inspiratory stertor. A computed tomography evaluation was performed and revealed an osteoproductive lesion primarily centered over the frontal bone with infiltration of the adjacent maxillary and nasal bones, focal intracranial invasion, and an associated broad-based, contrastenhancing, extra-axial lesion along the longitudinal cerebral fissure. Rhinoscopic and incisional biopsies of the paranasal mass were obtained, and a meningioma was diagnosed histologically. Based on the imaging features and histopathology results, an extracranial paranasal sinus meningioma was diagnosed in this dog. To the authors' knowledge, this is the first case report describing the computed tomographic findings associated with a secondary extracranial paranasal sinus meningioma in a dog. Key clinical message: Meningiomas in dogs can be present outside of the brain case and should be considered a differential for tumors of the paranasal sinuses.

Méningiome extra-crânien secondaire du sinus paranasal chez un chien. Un chien maltais de 13 ans a été présenté pour un stertor inspiratoire. Une évaluation par tomodensitométrie a été réalisée et a révélé une lésion ostéoproductive principalement centrée sur l'os frontal avec une infiltration des os maxillaires et nasaux adjacents, une invasion intracrânienne focale et une lésion extra-axiale à large base associée, augmentant le contraste, le long de la fissure cérébrale longitudinale. Des biopsies rhinoscopiques et incisionnelles de la masse paranasale ont été obtenues et un méningiome a été diagnostiqué histologiquement. Sur la base des caractéristiques d'imagerie et des résultats de l'histopathologie, un méningiome extra-crânien du sinus paranasal a été diagnostiqué chez ce chien. À la connaissance des auteurs, il s'agit du premier rapport de cas décrivant les résultats tomodensitométriques associés à un méningiome extra-crânien secondaire du sinus paranasal chez un chien.Message clinique clé :Les méningiomes chez le chien peuvent être présents en dehors du cerveau et doivent être considérés comme un différentiel pour les tumeurs des sinus paranasaux.(Traduit par Dr Serge Messier).

Ocular and periocular radiation toxicity in dogs treated for sinonasal tumors: A critical review.

Visual impairment from radiation-induced damage can be painful, disabling, and reduces the patient's quality of life. Ocular tissue damage can result from the proximity of ocular organs at risk to irradiated sinonasal target volumes. As toxicity depends on the radiation dose delivered to a certain volume, dose-volume constraints for organs at risk should ideally be known during treatment planning in order to reduce toxicity. Herein, we summarize published ocular toxicity data of dogs irradiated for sinonasal tumors from 36 publications (1976-2018). In particular, we tried to extract a dose guideline for a clinically acceptable rate of ocular toxicity. The side effects to ocular and periocular tissues were reported in 26/36 studies (72%) and graded according to scoring systems (10/26; 39%). With most scoring systems, however, toxicities of different ocular and periocular tissues are summed into one score. Further, the scores were mostly applied in retrospect and lack volume- and dose-data. This incomplete information reflects the crux of the matter for radiation dose tolerance in canine ocular tissues: The published information of the last three decades does not allow formulating dose-volume guidelines. As a start, we can only state that a mean dose of 39 Gy (given in 10 x 4.2 Gy fractions) will lead to loss of vision by one or both eyes, while mean doses of <30 Gy seem to preserve functionality. With a future goal to define tolerated doses and volumes of ocular and periocular tissues at risk, we propose the use of combined ocular toxicity scoring systems.

Equine sinonasal anaplastic sarcoma infected with multi-drug resistant Escherichia coli.

A 5-year-old Hanoverian horse was presented for a palpable and visible mass over the frontal and maxillary sinuses. Following endoscopy and radiography surgical excision was attempted. The horse was euthanized during surgery and samples of the mass were identified as malignant anaplastic sarcoma, a seldom reported sinonasal tumor in equids.

Sarcome anaplasique naso-sinusien équin infecté par Escherichia coli multirésistant aux antibiotiques. Un cheval Hanovrien âgé de 5 ans a été présenté pour une masse palpable et visible sur les sinus frontal et maxillaire. Après une endoscopie et la radiographie, une excision chirurgicale a été tentée. Le cheval a été euthanasié durant la chirurgie et des échantillons de la masse ont été identifiés comme un sarcome anaplasique malin, une tumeur naso-sinusienne rarement signalée chez les équidés.(Traduit par Isabelle Vallières).

Progressive ossifying paranasal sinus mass of suspected traumatic origin in a mare: Surgical treatment and follow-up.

This report describes a case of a multilobular, osseous mass including parts of the right orbit, concho frontal sinus and right ventral and dorsal conchal sinuses that developed after a traumatic insult to the right maxillary sinus 4 years prior to presentation. Surgical removal of the mass including parts of the bony orbit and long-term outcome are reported.

Masse des sinus paranasaux à ossification progressive d'origine traumatique soupçonnée chez une jument : traitement chirurgical et suivi. Ce rapport décrit une masse multilobulaire et osseuse comprenant des parties de l'orbite droite, des cornets nasaux frontaux et des sinus ventral et dorsal droits qui s'est développée après un traumatisme du sinus maxillaire droit 4 années avant la présentation. L'ablation chirurgicale de la masse, incluant des parties de l'orbite osseuse et les résultats à long terme sont signalés.(Traduit par Isabelle Vallières).

Experimental Transmission of Bighorn Sheep Sinus Tumors to Bighorn Sheep (Ovis canadensis canadensis) and Domestic Sheep.

Bighorn sheep sinus tumors are a recently described disease affecting the paranasal sinuses of Rocky Mountain bighorn sheep (Ovis canadensis canadensis). Several features of this disease suggest an infectious cause, although a specific etiologic agent has not been identified. To test the hypothesis that bighorn sheep sinus tumors are caused by an infectious agent, we inoculated 4 bighorn sheep lambs and 4 domestic sheep lambs intranasally with a cell-free filtrate derived from a naturally occurring bighorn sheep sinus tumor; we held 1 individual of each species as a control. Within 18 months after inoculation, all 4 inoculated domestic sheep (100%) and 1 of the 4 inoculated bighorn sheep (25%) developed tumors within the ethmoid sinuses or nasal conchae, with features similar to naturally occurring bighorn sheep sinus tumors. Neither of the uninoculated sheep developed tumors. Histologically, the experimentally transmitted tumors were composed of stellate to spindle cells embedded within a myxoid matrix, with marked bone production. Tumor cells stained positively with vimentin, S100, alpha smooth muscle actin, and osteocalcin, suggesting origin from a multipotent mesenchymal cell. A periosteal origin for these tumors is suspected. Immunohistochemical staining for the envelope protein of JSRV (with cross-reactivity to ENTV) was equivocal, and PCR assays specific for these agents were negative.

Rostral cranial fossa and sinonasal neoplasms with cribriform plate involvement in 32 dogs and 17 cats.

The rostral cranial fossa (RCF) consists of the sphenoid and ethmoid bones, which accommodate the olfactory bulbs and nerves along the recesses of the cribriform plate. Neoplasms located in the vicinities of the RCF can compress and/or invade the cribriform plate. Here we describe the clinical and pathologic findings of neoplasms involving the cribriform plate in 32 dogs and 17 cats autopsied over a 13-y period. The average ages of affected dogs and cats were 9.2 y and 9.7 y, respectively. No sex or breed predisposition was evident in dogs, but 13 of 18 cats were spayed females and 14 of 18 were domestic shorthair cats. The main clinical signs were seizures (10 cases) and epistaxis (5 cases) in dogs, and red-to-brown nasal discharge (5 cases) and seizures (4 cases) in cats. In dogs, the 22 sinonasal neoplasms included adenocarcinoma (14 cases), transitional carcinoma (4), squamous cell carcinoma (2), lymphoma (1), and histiocytic sarcoma (1); the 10 intracranial neoplasms consisted of high-grade gliomas (3 cases), psammomatous meningiomas (2), histiocytic sarcomas (2), olfactory neuroblastomas (2), and a meningeal granular cell tumor (1). In cats, the 14 sinonasal neoplasms included lymphoma (8 cases), adenocarcinoma (4), adenosquamous carcinoma (1), and squamous cell carcinoma (1); the 3 intracranial neoplasms consisted of oligodendroglioma (1), transitional meningioma (1), and olfactory neuroblastoma (1).

Sinonasal chondrosarcoma in a llama.

A 14-y-old intact female llama (Lama glama) was presented for evaluation of a right maxillary swelling of 3-mo duration. Clinically, the animal had mild nasal discharge, abnormal retropulsion of the right eye, and moderate gingival disease. An incisional biopsy of the maxillary mass revealed pleomorphic and mitotically active neoplastic spindle-to-stellate cells organized in haphazard lacunae embedded in abundant chondroid matrix. Given the poor prognosis, euthanasia was elected. Postmortem examination and sectioning of the head exposed a large solid, white, firm mass that vastly expanded the right infraorbital region, extending to the maxilla, effacing the right nasal conchae and ipsilateral zygomatic bone. Collectively, postmortem dissection, cytology, and histopathology of the primary mass supported a diagnosis of sinonasal chondrosarcoma. To our knowledge, this entity had not been reported previously in this species and should be considered a differential for facial deformities in New World camelids.

Comparison of standard radiography and computed tomography in 21 dogs with maxillary masses.

Imaging of patients with oral cancer is required to determine tumor extension in order to assist in prognosis and surgical planning. Conventional screen-film radiography (SFR) used to be the most common method for oral assessment, but computed tomography (CT) has become more available and is being used for obtaining complementary information. CT examinations eliminate superimposition by acquiring cross-sectional images of the region of interest. The objective of this study was to determine the diagnostic value of SFR compared with CT examinations for evaluation of oral masses in dogs. Twenty-one dogs received head and thorax SFR, and pre- and post-contrast head CT. Bony changes were observed in 80.9% and 95.2% of the cases in SFR and CT studies, respectively. Invasion of adjacent structures (i.e. nasal cavity, frontal and sphenoidal sinuses, orbit, maxillary recess, nasopharynx) was observed in only 30% of cases with SFR while CT showed 90.4% involvement. CT is an important preoperative examination modality and is more effective in identifying bone changes and tumor invasion of adjacent structures compared with SFR.

Frontal sinus carcinoma in forty-one dogs (2001-2022).

Reports on canine frontal sinus carcinomas (FSCs) are scarce. This retrospective review of 41 dogs with FSC (2001-2022) describes demographic and clinical characteristics of canine FSC and reports the clinical experience and overall survival following treatment with toceranib phosphate (TOC) and meloxicam in 10 cases. Median age at diagnosis was 10.6 years (range: 6.5-15.4 years). There was a male-to-female-ratio of 2.4:1. The most common breeds were Jack Russell Terriers (JRT) (n = 7; 17.1%) and Rottweilers (n = 3, 7.3%). Mesocephalic breeds (70.6%) were most commonly affected, brachycephalics accounted for 8.8%. The most frequent clinical signs included skull deformation dorsomedial to the eye (87.5%), pain/head-shyness (40.0%), ocular (22.5%)/nasal (17.5%) discharge, and exophthalmos (17.5%). Duration of symptoms prior to diagnosis varied from a few days to 9 months. There were no neurological signs at initial presentation despite imaging evidence of osteolysis of the lamina interna of the frontal bone in most dogs (69.4%). In 11.5%, pulmonary changes suggestive of metastasis or concurrent primary pulmonary neoplasia were present. Tumour types included squamous cell carcinoma (58.5%), unspecified carcinoma (29.3%), and adenocarcinoma (9.8%). Ten dogs were treated with TOC (median 2.8 mg/kg EOD or three times per week) and meloxicam (0.1 mg/kg, EOD) (TOC-M), resulting in subjective regression of skull deformity in 8/10 (80.0%) patients. Overall median survival time with TOC-M was 183.5 days (range: 120-434 days). FSCs typically present with skull deformation, but no overt neurological signs. Male dogs and JRT may be overrepresented. The use of TOC-M in FSC appears promising and warrants further prospective evaluation.

Paranasal sinus masses of Rocky Mountain bighorn sheep (Ovis canadensis canadensis).

This article describes 10 cases of paranasal sinus masses in Rocky Mountain bighorn sheep (Ovis canadensis canadensis). Among 21 bighorns that were examined from 11 herds in Colorado, 10 individuals (48%) from 4 herds (36%) had masses arising from the paranasal sinuses. Affected animals included 9 of 17 females (53%) and 1 of 4 males (25%), ranging in age from approximately 2 years to greater than 10 years. Defining gross features of these masses included unilateral or bilateral diffuse thickening of the respiratory lining of the maxillary and/or frontal sinuses, with abundant seromucinous exudate in the affected sinus cavities. Defining histologic features of these masses included chronic inflammation and proliferation of mesenchymal and epithelial cells of the mucosa and submucosa. Epithelial changes included hyperplasia of mucosal epithelium, hyperplasia of submucosal glands and ducts, and neoplasia (adenocarcinoma). Mesenchymal changes included submucosal myxedema, submucosal fibroplasia/fibrosis, bone destruction, and neoplasia (myxomatous fibroma). Specific immunohistochemistry and polymerase chain reaction for Jaagsiekte sheep retrovirus and enzootic nasal tumor virus were performed with negative results.

Clinical-dosimetric relationship between lacrimal gland dose and keratoconjunctivitis sicca in dogs with sinonasal tumors treated with radiation therapy.

BACKGROUND: Dogs with sinonasal tumor can develop keratoconjunctivitis sicca (KCS) after radiation therapy (RT). In humans, the incidence of xerophtalmia is associated with the mean radiation dose received by the ipsilateral lacrimal gland (LG). HYPOTHESIS/OBJECTIVES: The eyes receiving a higher mean LG dose are more likely to develop KCS. The aim of the study was to determine a starting threshold dose to use as dose constraint for intensity-modulated radiation therapy (IMRT). ANIMALS: Dogs with nasal tumors treated with RT between August 2013 and December 2016. METHODS: Case control retrospective study of dogs with sinonasal tumor treated with 42 Gray (Gy) in 10 fractions using IMRT. Dogs were included if development of KCS after RT was documented (cases) or adequate follow-up information with Schirmer tear test (STT) result for ≥6 months after RT was available (controls). Lacrimal glands were contoured and dose distribution was calculated using the original treatment plan to determine prescribed doses to LGs. RESULTS: Twenty-five dogs were treated with RT and 5 dogs (20%) developed KCS. Fifteen dogs met the inclusion criteria including 5 unilateral KCS and 10 control dogs, resulting in 5 KCS eyes and 25 control eyes. KCS developed at a median of 111 days (84-122) after 1st RT. The mean LG dose reached using a 4.2 Gy per fraction was 33.08 Gy (range: 23.75-42.33) for KCS eyes and 10.33 Gy (1.8-24.77) for control eyes (P < .001). The minimum LG mean dose for developing KCS was 23.75 Gy. No eyes that received a mean LG dose <20 Gy developed KCS versus 5/7 (71%) developed with >20 Gy. CONCLUSION AND CLINICAL IMPORTANCE: Contouring and applying a dose constraint on LGs should be performed when using IMRT in dogs with sinonasal tumors to reduce the risk of KCS.

Definitive-intent radiotherapy for sinonasal carcinoma in cats: A multicenter retrospective assessment.

Treatment of epithelial sinonasal tumours in cats is not commonly reported. In the newer reports, palliative radiation protocols have been described more often than definitive-intent protocols. In this multi-institutional retrospective study, we included 27 cats treated with single-modality radiotherapy. Cats were irradiated using 10 daily fractions of 4.2 Gy. Three cats (11.1%) experienced a complete clinical response and 17 (63%) had a partial clinical response. Stable clinical disease was noted in three cats (11.1%). Four cats (14.8%) showed progression within 3 months following treatment. The median time to progression for all cases was 269 days (95 % confidence intervals [CI]: 225; 314). The proportion of cats free of progression at 1 and 2 years was 24% (95% CI: 22%; 26%) and 5% (95% CI: 5%; 6%), respectively. None of the prognostic factors evaluated were predictive of outcome (anaemia, tumour volume at the time of staging, modified Adams stage, intracranial involvement, facial deformity, epistaxis, inappetence or weight loss). Median overall survival (OS) for all deaths was 452 days (95% CI: 334; 571). The proportion of cats alive at 1 and 2 years was 57% (95% CI: 37%; 77%) and 27% (95% CI: 25%; 29%), respectively. Surprisingly, cats with epistaxis had a longer median OS of 828 days (95% CI: 356; 1301) compared to 296 days (95% CI: 85; 508) in cats without epistaxis, (P = .04, Breslow). Radiation therapy used as a single modality for the treatment of feline sinonasal carcinoma improved clinical signs and was well tolerated but progression within a year was common.

Pneumocephalus secondary to removal of an osteoma from the paranasal sinuses of a horse.

CASE DESCRIPTION: A 2-year-old Quarter Horse was evaluated because of a progressive left-sided facial deformity and unilateral nasal and ocular discharge. CLINICAL FINDINGS: Physical examination revealed convexity of the left frontonasal region, left-sided nasal and ocular discharge, and decreased air flow through the left nares. Radiography and computed tomography revealed an extensively mineralized mass occupying most of the left paranasal sinuses. TREATMENT AND OUTCOME: The mass was surgically debulked, but complete removal was precluded because the mass was tightly adhered to the frontal and maxillary bones. Results of histologic examination of the mass were consistent with a diagnosis of osteoma. The horse developed transient pyrexia and colic following surgery, and postoperative radiography revealed gas opacities in the lateral ventricles of the brain, consistent with iatrogenic pneumocephalus. However, the horse did not develop any neurologic signs and was performing normally 2 years after surgery. CLINICAL RELEVANCE: Findings reinforce concerns that paranasal sinus surgery in horses can be associated with intracranial complications such as pneumocephalus. In horses with a mass involving the paranasal sinuses, computed tomography may be helpful in determining the boundaries of the mass and formulating a surgical treatment plan.

Sinonasal tumor in 3 dogs after successful topical treatment for frontal sinus aspergillosis.

Three dogs diagnosed with aspergillosis developed sinonasal tumors several months after successful treatment with topical clotrimazole solution. Chronic rhinosinusitis was also detected in all cases prior to diagnosis of sinonasal tumors. The inflammatory response to Aspergillus, clotrimazole treatment, and chronic inflammation after treatment are discussed as possible neoplastic promoting factors.

Surgical complications of the equine upper respiratory tract.

Upper respiratory abnormalities are common performance-limiting problems in horses. The complications of various treatment methods, including laryngoplasty surgery, sinus surgery, intermittent dorsal displacement of the soft palate, laser surgery, and tracheal disorders, are discussed.

Three cases of osteoma and an osseous fibroma of the paranasal sinuses of horses in South Africa.

Four horses were presented to the Onderstepoort Veterinary Academic Hospital with histories of facial asymmetry, nasal discharge or obstruction of normal nasal passage airflow. Radiographic examination of the maxillary sinuses of 2 cases revealed well circumscribed, unilateral, mineralised masses; the other 2 cases showed less mineralisation. The masses were accessed for further investigation by surgically created frontonasal bone flaps or trephination of the maxillary sinuses. Diagnosis of osteoma was confirmed histopathologically in 3 of the cases and of ossifying fibroma in the 4th. Two horses were euthanased directly after surgical intervention due to poor prognosis. Osteomas are by nature expansile tumours and follow the complex communication of the sinuses, and therefore are not all amenable to surgical removal. Osseous fibromas are large, solitary, expansile lesions that are rare in all species but reported most frequently in horses. They have an apparent predilection for the rostral mandible of the horse.

Calcified tumours of the paranasal sinuses in three horses.

Three horses, a 10-year-old Thoroughbred mare, a 9-year-old Thoroughbred gelding and a 6-year-old Arab gelding, with calcified tumours of the paranasal sinuses, are described. All horses presented with purulent nasal discharges and facial distortion. Exophthalmos, blepharospasm and ocular discharge were also a feature in individual horses. A presumptive diagnosis of a calcified tumour was made on the basis of clinical signs and radiographic and endoscopic findings. The tumours ranged from 15 to 25 cm in diameter. A large frontonasal bone flap was used to expose the tumours, which were cleaved into several pieces with an osteotome and removed. Histological examination of the masses identified cementomas in two cases and an osteoma in the third. Long term follow up from 18 months to 5 years after surgery indicated that there was no recurrence. This case series demonstrates that, although calcified tumours of the paranasal sinuses are rare in horses, they should be considered in the differential diagnosis of purulent nasal discharge, facial swelling and ocular distortion, and are amenable to surgical treatment.

Patient characteristics influencing the variability of distributed parameter-based models in DCE-CT kinetic analysis.

Kinetic parameter variability may be sensitive to kinetic model choice, kinetic model implementation or patient-specific effects. The purpose of this study was to assess their impact on the variability of dynamic contrast-enhanced computed tomography (DCE-CT) kinetic parameters. A total of 11 canine patients with sinonasal tumours received high signal-to-noise ratio, test-double retest DCE-CT scans. The variability for three distributed parameter (DP)-based models was assessed by analysis of variance. Mixed-effects modelling evaluated patient-specific effects. Inter-model variability (CVinter ) was comparable to or lower than intra-model variability (CVintra ) for blood flow (CVinter :[4-28%], CVintra :[28-31%]), fractional vascular volume (CVinter :[3-17%], CVintra :[16-19%]) and permeability-surface area product (CVinter :[5-12%], CVintra :[14-15%]). The kinetic models were significantly (P<0.05) impacted by patient characteristics for patient size, area underneath the curve of the artery and of the tumour. In conclusion, DP-based models demonstrated good agreement with similar differences between models and scans. However, high variability in the kinetic parameters and their sensitivity to patient size may limit certain quantitative applications.