Inflammatory polyps of the middle ear in 5 dogs

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.

Canine Tonsillar Polyps: Characteristics, Classification, and Review of the Pathogenesis

Canine tonsillar polyps are uncommon. We describe 14 tonsillar polyps in dogs and review their classification and pathogenesis. All dogs were adult (3-13 years old). Females (10/14) were more affected than males (4/14). Most of the lesions were asymptomatic (10/14). All lesions were unilateral, pedunculated (9/14), or sessile (5/14), with a smooth (12/14) or papillary/verrucous surface (2/14). Histologically, polyps consisted of benign proliferation of lymphatic vessels, blood vessels, fibrous tissue, and lymphoid tissue in variable proportions, with occasional adipose tissue (4/14). According to the main stromal components, polyps were categorized as lymphangiomatous (5/14), lymphangiolipomatous (2/14), lymphangiofibromatous (2/14), angiofibromatous (1/14), angiofibrolipomatous (1/14), lymphoid (2/14), and myxomatous (1/14). As the pathogenesis of these polyps remains unclear, we propose to replace the term inflammatory tonsillar polyp by a morphological diagnosis based on the stromal characteristics of the lesions. Simple surgical excision was curative in the 9 cases with available follow-up information.

Recurrent polyp formation with Candida tropicalis infection and otitis in a dog

To describe a case of a recurrent Candida tropicalis otitis externa, media and interna in a dog with an ear polyp. A 9-year-old Irish Setter was presented with 2 episodes of otitis sinistra, left-sided vestibular syndrome and Horner syndrome 7 months apart. At the first episode a benign ear polyp was extracted and Candida tropicalis cultured from the left middle ear. The neurological signs disappeared within 7 days, the Candida infection was more difficult to treat. Seven months later, a polyp was found in the ear again and cytology was consistent with Candida tropicalis. A unilateral left total ear canal ablation with lateral bulla osteotomy was performed and a middle ear culture confirmed Candida tropicalis. Treatment led to resolution of clinical signs. Candida tropicalis, an emerging pathogen, should be considered in cases of recurrent yeast otitis and may be difficult to treat.

Traumatic Tympanic Bulla Fracture in a Cat With Severe Head Trauma

A nine-year-old male European shorthair cat was referred to our practice with severe head trauma after suffering a road traffic accident (RTA). The patient presented marked facial swelling and multiple skin wounds and bruising, inspiratory dyspnea, palpable mandibular and maxillary fractures, serosanguinolent oronasal discharge and right eye exophthalmos and buphthalmos with loss of menace and pupillary reflex. After stabilizing the patient, a CT scan was performed under general anesthesia and an oesophagostomy tube was placed. The scan revealed the presence of multiple right tympanic bulla fractures. Multiple mandibular, maxillary, and palatine fractures were also present. The cat underwent surgery. Mandibular symphyseal separation and maxillary fractures were stabilized using intraoral cerclage wire fixation reinforced with composite and the right eye was enucleated. The rest of the fractures were treated conservatively. A CT scan 4 months after the trauma was also performed. At this point, the maxillofacial fractures were healing properly, and a bone callus demonstrating fusion of fragments of the right tympanic bulla was evident. There was absence of abnormal content inside the right tympanic bulla. The patient recovered uneventfully with no neurological deficits. To the author's knowledge this is the first case reporting a traumatic tympanic bulla fracture in the cat with case follow up, and the first case reported using CT as diagnostic imaging test.

Cholesteatoma and meningoencephalitis in a dog with chronic otitis externa

A 10-year-old female spayed German Shepherd dog, with a year-long history of recurrent left ear infections, was presented for progressive ataxia, head tilt, and pain on opening of the mouth. On physical examination, a large amount of ceruminous debris was present in the left ear and multiple neurologic defects localizing to the cerebellum and vestibular system were identified. Magnetic resonance imaging (MRI) demonstrated a minimally contrast-enhancing mass within the left bulla, an intracranial space-occupying, heterogeneously contrast-enhancing lesion at the level of the left cerebello-medullary junction, and contrast enhancement of the ipsilateral meninges. Cerebrospinal fluid analysis revealed a marked mixed cell pleocytosis (nucleated cell count 655 cells/μL). The mass was visualized within the horizontal ear canal by otoscopic examination and a biopsy was taken. Impression smears of the biopsy contained many anucleate keratinized squamous epithelial cells, mild mixed inflammation, and few presumptive fibroblasts. With the provided clinical history and MRI findings, a cytologic diagnosis of cholesteatoma was made. A ventral bulla osteotomy was performed, and histopathologic examination of resected tissue confirmed the cytologic diagnosis of cholesteatoma. The dog's clinical symptoms improved postoperatively, but the dog died of unrelated causes, 3.5 months later. To our knowledge, this is the first description of the cytologic features of a cholesteatoma, which is a nonneoplastic, but locally invasive epidermoid cyst, in the middle ear of dogs.

Traumatic tympanic bulla fracture

A Pekingese dog was presented for evaluation of head trauma with ventral head and neck swelling, puncture wounds, palpable mandibular fractures, and loss of menace, severe miosis, and loss of palpebral reflex of the right eye. Computed tomography confirmed multiple mandibular and zygomatic fractures, a right ear canal avulsion, and a complete right tympanic bulla fracture with ventral displacement. The tympanic bulla fracture was managed conservatively. Topical lubrication and antibiotic ointment was prescribed for the right eye. A subtotal hemimandibulectomy was performed to address the mandibular fractures. A temporary oesophagostomy feeding tube was placed. No short-term complications developed as a result of the fractured bulla and avulsed ear canal being left in situ, and no complications were reported 18 months after the injury. To the authors' knowledge this is the first report of a traumatic tympanic bulla fracture in the dog.

Inflammatory polyps and aural neoplasia

Although aural neoplasia is a relatively uncommon entity in companion animals, it remains a group of heterogeneous conditions that can have a significant negative impact on quality and duration of life of dogs and cats. Chronic ear disease that responds poorly or partially to empiric therapy should raise the suspicion that an underlying condition, such as neoplasia, may be the perpetrator of inflammation. Early diagnosis followed by appropriate therapy improves the likelihood of disease control and prolonged survival.

Neurologic evaluation of the ear

Diseases of the ear often cause signs of neurologic dysfunction because of damage of peripheral nervous system structures associated with the middle and inner ear. Vestibular dysfunction, facial paralysis, Horner's syndrome, and hearing deficits are the most common neurologic deficits that accompany middle and inner ear disease. Differentiating these signs from disease of the central nervous system is crucial for an accurate diagnosis and prognosis but can be difficult. Understanding the normal anatomy of the ear and its association with the brain is crucial to interpretation of the neurologic examination. This article reviews neurologic dysfunction commonly associated with diseases of the ear and differentiating these signs from central disease.