[Unusual presentation of a mast cell tumor in the ear canal of a cat]. / Ungewöhnlicher Mastzelltumor im Gehörgang einer Katze.

A 12-year-old male neutered European Shorthair cat was presented for pruritus in the right ear region, bleeding from ear canal and a suspected polyp-like mass in its lumen.After the diagnostic imaging a biopsy of the mass was taken and submitted for histopathological evaluation. Histopathologic examination led to the diagnosis of low grade mast cell tumor. The subsequent staging examinations included ultrasonography of the liver and spleen as well as a complete blood count. Total ear canal ablation was performed on the same day, and the removed ear canal was again submitted for histopathologic evaluation of the surgical margins. The excision incision margins were free from infiltrating tumor cells. The cat was euthanised 14 months after the surgery. It is unknown whether the reasons for this were associated to metastatic spread of the initial mast cell tumor.A mast cell tumor in the ear canal is an unusual and rare finding, however it should be included in the list of differential diagnoses for ear canal tumors.

Evaluation of aural masses submitted as inflammatory polyps in 20 dogs (2000-2020).

BACKGROUND: Canine non-neoplastic aural polypoid masses (APMs) are uncommon, with few published studies. OBJECTIVES: The aim of this retrospective study was to characterise the clinical presentation, diagnostic imaging and histopathological results for APMs submitted as aural inflammatory polyps (AIPs). ANIMALS: Twenty dogs with APMs evaluated at a veterinary teaching hospital. MATERIALS AND METHODS: Cases were selected by searching computerised medical records from 2000 to 2020, using keywords 'canine', 'aural/otic polyp' and 'aural/otic inflammatory mass'. Histological samples and medical records were reviewed. RESULTS: In 14 of 20 dogs, external ear canal masses were characterised by keratinised squamous epithelium with or without adnexa. Tympanic bulla origin was confirmed in four of 20 dogs by the presence of cuboidal to ciliated columnar epithelium, with or without squamous epithelium. The site of origin could not be determined in two dogs. Diagnostic imaging (MRI or CT) confirmed APM presence in 14 of 20 dogs. Otitis media was diagnosed in four of four tympanic bulla APMs and seven of 13 ear canal APMs. In 18 of 20 dogs, debulking, traction avulsion, and total ear canal ablation and bulla osteotomy led to APM resolution in two of eight, four of six and four of four dogs, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Type of epithelium was a key feature in determining the APM origin, and interpretation in conjunction with video otoscopy and diagnostic imaging was crucial. Canine APMs more commonly arose from the ear canal. Tympanic bulla APMs and APMs of undetermined origin were comparable to feline AIPs. Regardless of APM origin site, debulking had the greatest likelihood of recurrence.

Clinical presentation and outcome in cats with aural squamous cell carcinoma: a review of 25 cases (2010-2021).

CASE SERIES SUMMARY: Ear canal neoplasia is uncommon in cats. Ceruminous gland adenocarcinoma is the most frequently reported malignant neoplasm of the feline ear canal, and squamous cell carcinoma (SCC) is the most common malignant neoplasm diagnosed in the feline middle ear. However, limited information exists on the outcome of cats diagnosed with SCC of the ear canal, middle or inner ear. Therefore, the objective of this study was to describe the outcome of cats diagnosed with SCC affecting these locations. Medical records were reviewed at multiple institutions to identify cats with a definitive diagnosis of SCC. Twenty-five cats were identified. Eleven cats were treated with surgery, eight with medical management, two with coarse fractionated radiation therapy, two with a combination of coarse fractionated radiation therapy and chemotherapy, one with a combination of surgery and coarse fractionated radiation therapy, one cat with systemic chemotherapy and one cat received no treatment following diagnosis. The median survival time of cats treated with surgery was 168 days vs 85 days (P = 0.28) for those treated palliatively with either medical management, radiation therapy, chemotherapy, or a combination of radiation therapy and chemotherapy. RELEVANCE AND NOVEL INFORMATION: This case series documented that SCC of the ear canal, middle and/or internal ear is a locally aggressive tumor that carries an overall poor prognosis. The median survival time for cats treated with surgery was longer than that with any other modality, but this difference was not statistically significant.

Endolymphatic sac tumor in an 8-month-old cat.

Background: The endolymphatic sac is an organ devoid of sensory receptors. It is connected with the endolymphatic compartment and contains endolymph. Endolymphatic sac tumor (ELST) is a rare neoplasm involving the middle and inner ear described in humans and dogs that does not show cellular characteristics of malignancy, but can be locally invasive and involve destruction of the temporal bone and adjacent structures. Case Description: An 8-month-old female cat was referred because of sudden onset of vestibular signs starting 3 days prior to referral. On clinical examination, the patient showed depression, right head tilt, left-sided facial paralysis, and horizontal nystagmus with fast phase to the left. The magnetic resonance images showed a voluminous extra-axial lesion, with irregular morphology and well-defined margins, with intracranial extension in the region of the pons, rostral medulla oblongata, cerebellar vermis, floccule, and left cerebellar hemisphere. Due to progressive clinical deterioration, the cat was euthanized 2 weeks later. A necropsy was then performed and histological samples were taken. The necropsy revealed the presence of a voluminous dark red irregular mass extending from the tympanic bulla to the posterior cranial fossa following the left glossopharyngeal nerve. The histopathological exam of the extra-axial lesion featured a nonencapsulated, moderately cellular, rather loose, proliferation of cuboidal to columnar epithelium breaching through chunks of an otherwise normal appearing dura mater and invading some cranial nerves. Sections of the cerebellum and brainstem revealed moderate, focal, impingement of the parenchyma with a very mild extension of the proliferating cells into the ventral left side of the medulla oblongata. Based on these histological characteristics, the lesion was defined as ELST, a rare neoplasm described in human beings and with two reports in dogs. Conclusion: To our knowledge, this is the first report describing an ELST in a cat.

Bilateral cholesterol granulomas in the middle ear cavities of a cat with sinonasal disease successfully removed via video-otoscopy.

CASE DESCRIPTION: A 9-year-old spayed female Maine Coon cat was presented at the University of Veterinary Medicine Vienna for further investigation of chronic nonpruritic bilateral ear disease and unilateral Horner syndrome. CLINICAL FINDINGS: Physical examination and otoscopy findings included right sided Horner syndrome, a right head tilt of approximately 20° and a small pink nodule in the right and several smaller nodules in the left proximal horizontal external ear canal. Computed tomography and magnetic resonance imaging revealed soft tissue opacity material in both middle ear cavities, the caudal portion of the nasal cavity, the left nasopharyngeal meatus and the right frontal sinus. Via videootoscopy, 2 multilobular and several flat nodules were detected in the proximal right horizontal external ear canal and in the left tympanic bulla, respectively. Histopathological examination confirmed the diagnosis of cholesterol granulomas. TREATMENT AND OUTCOME: All otic cholesterol granulomas (CGs) were removed via video-otoscopy (VO), and topical treatment was initiated in addition to oral prednisolone. After the histopathological confirmation, negative microbial cultures from the middle ear cavities, and the remission of the symptoms by the first recheck, topical, and systemic treatment were discontinued. A follow-up 6 months later, did not reveal any recurrence of the CGs. CLINICAL RELEVANCE: To our knowledge, this is the first case of bilateral CGs diagnosed with a combination of CT, MRI, VO, and histopathology and removed minimal invasively via VO, without a need for ventral bulla osteotomy, which led to complete remission of all signs and no relapse until the follow up 6 months later.

Aural Hematoma Secondary to Hemangiosarcoma in a Domestic Cat-Case Report.

A 7-year-old, white, domestic short hair, female cat was presented with an aural hematoma of the right pinna, which had been partially resected a year previously. A 3 × 4 cm mass, macroscopically similar to an auricular hematoma, was visible on the convex surface and a smaller vascular lesion was present on the ear margin. Cytological examination of the smaller mass was suggestive of hemangiosarcoma, and a diagnosis confirmed by histopathologic and immunohistochemical tests. Complete pinnectomy with a wide margin was performed and during the 3-year follow-up, the cat had no local recurrence or metastasis. We conclude that hemangiosarcoma should be considered as a potential differential diagnosis in white-coated cats with an unusual clinical presentation of aural hematoma.

[Atrial dissociation in a boxer with a carcinoma of the middle ear]. / Atriale Dissoziation bei einem Boxer mit Mittelohrkarzinom.

INTRODUCTION: The case report describes an atrial dissociation in a 9-year-old male boxer diagnosed by ECG and echocardiography. Torticollis, severe neck pain and auscultatory arrhythmia were found during the clinical examination. In addition, a mass was found in the left tympanic bulla and histologically a carcinoma of the middle ear was diagnosed.

INTRODUCTION: La présente étude de cas décrit une dissociation auriculaire chez un boxer mâle de 9 ans diagnostiquée par ECG et échocardiographie. Lors de l'examen clinique on a relevé un port de tête penché, des douleurs cervicales sévères et une arythmie à l'auscultation. De plus, une masse a été trouvée dans la bulle tympanique gauche et un carcinome de l'oreille moyenne a été diagnostiqué histologiquement.

Invasive histiocytoma in the ear canal of a dog.

BACKGROUND: Cutaneous histiocytomas (CH) are derived from epidermal Langerhans cells. Single CH are generally associated with a good prognosis in dogs because most undergo spontaneous remission. However, aggressive behaviour and lymph node metastasis have been reported in a small number of dogs with single CH. OBJECTIVE: To describe the clinical presentation, treatment and disease progression of an aggressive CH located in the ear canal of a dog. ANIMAL: An 8-year-old intact male Rottweiler dog. METHODS AND MATERIALS: A unilateral ear canal mass was identified as a CH on routine haematoxylin and eosin stained samples. The diagnosis was confirmed by the demonstration of markers associated with Langerhans cells (Iba-1, E-cadherin and CD18) and the absence of markers associated with B cells (CD79a, CD20, Pax5), T cells (CD3), plasma cells (Mum-1) and macrophages (CD11d, CD204). RESULTS: A total ear canal ablation was performed, but tumour cells extended throughout the horizontal canal and to the deep surgical margin. Due to the locally invasive nature of the mass and incomplete excision, adjunctive chemotherapy with CCNU was pursued. No measurable local disease was appreciable at the time of the last treatment. At 250 days post-surgery the dog was euthanized owing to the development of multiple abdominal masses. No evidence of local tumour recurrence was noted. CONCLUSIONS AND CLINICAL IMPORTANCE: Although single CH are typically associated with benign behaviour, the mass in this dog demonstrated locally invasive behaviour. Cutaneous histiocytomas in the ear canals of dogs may represent a particularly aggressive variant of the condition.

Partial vertical ear canal resection in two cats.

CASE DESCRIPTION: An 18-year-old domestic medium-hair cat (cat 1) and a 16-year-old domestic shorthair cat (cat 2) were evaluated because of obstructive skin lesions involving the perimeter of the left external auditory canal. CLINICAL FINDINGS: Otitis externa was present in affected ears secondary to obstructive soft tissue growths involving the outer margin of the external auditory canal and outer third of the vertical ear canal. Histologic examination of a preoperative biopsy sample revealed multiple ulcerated ceruminous gland adenomas in the affected ear of cat 1. Histologic examination of the submitted tissue from cat 2 confirmed ceruminous cystomatosis with surface colonization of yeast compatible with Malassezia spp. TREATMENT AND OUTCOME: Both cats underwent partial resection of the upper third of the affected vertical ear canal and associated diseased skin. The incised margin of the pinna was sutured to the margin of the remaining portion of the vertical ear canal with absorbable sutures. Both cats were disease free over a 12-month (cat 1) or 10-month (cat 2) follow-up period. Cat 1 later developed a small ceruminous gland adenocarcinoma in the adjacent rostrolateral margin of the vertical ear canal 1 year after surgery; the mass was resected, and the patient was free of recurrence 4 months later. CLINICAL RELEVANCE: Partial resection was an effective alternative to complete vertical ear canal resection for lesions involving the upper third of the vertical ear canal in these cats; the partial resection procedure was deemed simpler to perform and less traumatic to the cat. Functional and cosmetic results were excellent, with preservation of the overall anatomy of the external auditory canal.

Congenital extraneural hemangioblastoma in a lamb.

A 1-mo-old Ivesi male lamb was presented with 2 large red masses on the skin of the left ear. The tumors were removed using gentle dissection and submitted for histologic evaluation. The tumors consisted of numerous thin-walled capillaries lined by endothelial cells and nests of stromal cells. Immunohistochemically, the endothelial cells were positive for CD45, and the stromal cells were positive for neuron-specific enolase. GFAP-positive cells were occasionally present within the tumor. Endothelial and stromal cells were negative for S100, CD34, CD31, and factor VIII-related antigen. The tumor had strong gross, microscopic, and immunohistochemical similarities with human extraneural hemangioblastoma.

Chondroblastic osteosarcoma of the middle ear in a guinea pig (Cavia porcellus).

A 3-year-old intact female guinea pig (Cavia porcellus) was presented for acute anorexia. Medical and surgical treatments for cystitis and ovarian cysts, respectively, did not prevent continuous weight loss. Computed tomography and histopathological analysis revealed a chondroblastic osteosarcoma of the right middle ear, which has not been reported in this species.

Ostéosarcome chondroblastique de l'oreille moyenne chez un cobaye(Cavia porcellus). Un cobaye (Cavia porcellus) femelle de 3 ans a été présentée pour une anorexie d'apparition aiguë. Malgré la prise en charge médicale et chirurgicale d'une cystite et de kystes ovariens, l'individu continuait de perdre du poids. L'examen tomodensitométrique et l'analyse histologique ont mis en évidence un ostéosarcome chondroblastique de l'oreille moyenne, ce qui n'a jamais été rapporté dans cette espèce.(Traduit par Dre Ophélie Cojean).

Well-differentiated liposarcoma with chondroid metaplasia in the auricle of a dog.

A 13-year-old spayed female dog had a mass in the left auricle. Grossly, connection between the mass and original auricular cartilage was not recognized. The mass was unencapsulated and contained multiple islands of mature hyaline cartilage and neoplastic adipocytes. The neoplastic cells comprised predominant mature adipocytes, scattered lipoblasts and irregular round to spindle cells with moderate atypia. The atypical cells occasionally had lipid droplets. A diagnosis of well-differentiated liposarcoma (WDL) with chondroid metaplasia was made. This is the first report for liposarcoma with chondroid metaplasia in the auricle of domestic animals.

Endolymphatic Sac Tumor in Two Dogs.

Endolymphatic sac tumors (ELSTs) are rare neoplasms of the inner and middle ear described in humans. Diagnosis of such neoplasms is difficult and largely dependent on a combination of histologic, immunohistochemical, and clinical findings. Although the neoplastic cells lack cellular features of malignancy, these are clinically aggressive tumors that often invade the surrounding temporal bone. Here, we describe 2 dogs with middle ear masses that share morphologic, immunohistochemical, and clinical similarities with human ELSTs. Advanced imaging of the masses revealed evidence of aggressive behavior such as bony lysis of the temporal bone. Histologically, the neoplastic epithelial cells formed papillary structures, lacked mitotic figures, and had mild anisocytosis and anisokaryosis. The neoplastic cells were immunohistochemically positive for cytokeratin AE1/AE3 but were negative for chromogranin, synaptophysin, and thyroglobulin. Local invasion and bone destruction but no evidence of metastases suggest a clinical behavior similar to human ELSTs.

Middle ear polyps: results of traction avulsion after a lateral approach to the ear canal in 62 cats (2004-2014).

Objectives The objective of this study was to report the surgical outcome and complication rate of deep traction avulsion (TA) of feline aural inflammatory polyps after a lateral approach (LA) to the ear canal. Methods This was a retrospective analysis of data retrieved from an electronic database of 62 cats treated with TA after an LA (TALA) for removal of ear canal polyps. Long-term outcome was assessed via a telephone questionnaire survey with the owners. Results Domestic shorthair cats (48%) and Maine Coons (37%) were over-represented. The most common presenting clinical signs were otorrhoea, ear scratching and head shaking. Video-otoscopic examination confirmed a polypous mass in the ear canal in all patients. All 62 cats underwent TALA, with a mean surgical time of 33 mins for experienced surgeons (n = 4) and 48 mins (n = 12) for less experienced surgeons. The recurrence rate of polyp regrowth for experienced surgeons was 14.3% vs 35% for the less experienced surgeons. Postoperative complications included Horner's syndrome (11.5%) and facial nerve paralysis (3%). Otitis interna was not observed. Conclusions and relevance A lateral approach to the ear canal in combination with deep TA of an aural inflammatory polyp is an effective first-line technique that results in a low recurrence and complication rate.

Concurrent Transitional Meningioma and Ceruminous Gland Adenocarcinoma in a Scottish Wildcat Hybrid (Felis silvestris).

The Scottish wildcat (Felis silvestris) is an iconic and endangered subpopulation of the European wildcat (F. silvestris silvestris). There is much research devoted to the ecology, genetics and conservation of this animal, but little published information on pathology and disease. The investigation and reporting of such information is vital to furthering understanding of the effects of hybridization, a factor that is crucial if we are to secure a future for the Scottish wildcat. This report describes the clinical presentation, gross post-mortem and histological findings in an elderly Scottish wildcat hybrid with concurrent transitional meningioma and ceruminous gland adenocarcinoma.

Ear Mite Removal in the Santa Catalina Island Fox (Urocyon littoralis catalinae): Controlling Risk Factors for Cancer Development.

Ear mites (Otodectes cynotis) and ear canal tumors are highly prevalent among federally endangered Island foxes (Urocyon littoralis catalinae) living on Santa Catalina Island off the coast of Southern California. Since studies began in the 1990s, nearly all foxes examined were found to be infected with ear mites, and ceruminous gland tumors (carcinomas and adenomas) were detected in approximately half of all foxes ≥ 4 years of age. We hypothesized that reduction of ear mite infection would reduce otitis externa and ceruminous gland hyperplasia, a risk factor for tumor development. In this study, we conducted a randomized field trial to assess the impact of acaricide treatment on ear mite prevalence and intensity of infection, otitis externa, ceruminous gland hyperplasia, and mite-specific IgG and IgE antibody levels. Treatment was highly effective at eliminating mites and reducing otitis externa and ceruminous gland hyperplasia, and mite-specific IgG antibody levels were significantly lower among uninfected foxes. Ceruminous gland hyperplasia increased in the chronically infected, untreated foxes during the six month study. Our results provide compelling evidence that acaricide treatment is an effective means of reducing ear mites, and that mite removal in turn reduces ear lesions and mite-specific IgG antibody levels in Santa Catalina Island foxes. This study has advanced our understanding of the underlying pathogenesis which results in ceruminous gland tumors, and has helped inform management decisions that impact species conservation.

Cutaneous Epitheliotropic T-Cell Lymphoma in a Marsh Rice Rat (Oryzomys palustris).

Published reports of spontaneous neoplasia in marsh rice rats (Oryzomys palustris) are sparse. We report here a case of cutaneous epitheliotropic T-cell lymphoma in a 14-mo-old marsh rice rat that involved the ear pinnae, with dissemination to the liver and spleen. Histologically, the thickened ear pinnae showed diffuse infiltration of neoplastic lymphocytes into the epidermis, dermis, and adnexal skin structures, with Pautrier microaggregations present in the epidermis. In addition, neoplastic lymphocytes were observed infiltrating and disrupting the architecture of the liver and spleen. Neoplastic lymphocytes were strongly positive for the T-cell marker CD3 but were negative for the B-cell markers CD19 and CD20. These histologic and immunohistochemical features are consistent with an epitheliotropic T-cell lymphoma, as previously reported in other species, including humans. To our knowledge, this report represents the first published case of spontaneous cutaneous epitheliotropic T-cell lymphoma in a marsh rice rat.