Segmental mandibulectomy as a novel adjunct management strategy for the treatment of an advanced cholesteatoma in a dog.

A 6-year-old spayed female Labrador retriever dog was evaluated for trismus and peripheral vestibular syndrome. Computed tomography (CT) revealed a mass arising from the tympanic bulla consistent with a cholesteatoma. A total ear canal ablation, bulla osteotomy, and adjunct segmental mandibulectomy were performed. Re-evaluation 2 weeks after surgery revealed no neurologic abnormalities, normal jaw range of motion, and no discomfort. Despite concern for recurrence of cholesteatoma based on CT imaging performed 33 months after surgery, repeat surgical intervention was not pursued as the owner considered the dog's comfort level to be satisfactory. The patient continued to do well for the 42-month follow-up period.

Mandibulectomie segmentaire comme nouvelle stratégie de gestion complémentaire pour le traitement d'un cholestéatome avancé chez un chien. Une femelle Labrador retriever de 6 ans stérilisée a été évaluée pour du trismus et un syndrome vestibulaire périphérique. La tomodensitométrie a révélé une masse issue de la bulle tympanique, compatible avec un cholestéatome. Une ablation totale du conduit auditif, une ostéotomie de la bulle et une mandibulectomie segmentaire complémentaire ont été réalisées. La réévaluation deux semaines après l'opération n'a révélé aucune anomalie neurologique, une amplitude de mouvement normale de la mâchoire et aucun inconfort. Malgré l'inquiétude suscitée par la récurrence du cholestéatome sur la base d'une tomodensitométrie réalisée 33 mois après la chirurgie, aucune nouvelle intervention chirurgicale n'a été envisagée, le propriétaire ayant estimé que le niveau de confort du chien était satisfaisant. La patiente a continué à bien se porter pendant la période de suivi de 42 mois.(Traduit par les auteurs).

Bilateral tympanokeratomas (cholesteatomas) with bilateral otitis media, unilateral otitis interna and acoustic neuritis in a dog.

BACKGROUND: An aural cholesteatoma, more appropriately named tympanokeratoma, is an epidermoid cyst of the middle ear described in several species, including dogs, humans and Mongolian gerbils. The cyst lining consists of stratified, keratinizing squamous epithelium with central accumulation of a keratin debris. This case report describes vestibular ganglioneuritis and perineuritis in a dog with chronic otitis, bilateral tympanokeratomas and presumed extension of otic infection to the central nervous system. CASE PRESENTATION: An 11-year-old intact male Dalmatian dog with chronic bilateral otitis externa and sudden development of symptoms of vestibular disease was examined. Due to the dog's old age the owner opted for euthanasia without any further examination or treatment and the dog was submitted for necropsy. Transection of the ears revealed grey soft material in the external ear canals and pearly white, dry material consistent with keratin in the tympanic bullae bilaterally. The brain and meninges were grossly unremarkable. Microscopical findings included bilateral otitis externa and media, unilateral otitis interna, ganglioneuritis and perineuritis of the spiral ganglion of the vestibulocochlear nerve and multifocal to coalescing, purulent meningitis. A keratinizing squamous epithelial layer continuous with the external acoustic meatus lined the middle ear compartments, consistent with bilateral tympanokeratomas. Focal bony erosion of the petrous portion of the temporal bone and squamous epithelium and Gram-positive bacterial cocci were evident in the left cochlea. The findings suggest that meningitis developed secondary to erosion of the temporal bone and ganglioneuritis and/or perineuritis of the vestibulocochlear nerve. CONCLUSIONS: Middle ear tympanokeratoma is an important and potentially life-threatening otic condition in the dog. Once a tympanokeratoma has developed expansion of the cyst can lead to erosion of bone and extension of otic infection to the inner ear, vestibulocochlear ganglion and nerve potentially leading to bacterial infection of the central nervous system.

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.

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.

Ovarian cholesteatoma in a bitch / Colesteatoma ovariano em uma cadela

O presente relato descreve um caso de colesteatoma ovariano em uma cadela Yorkshire de 15 anos de idade. O diagnóstico clínico foi de piometra e o animal foi submetido a ovariosalpingohisterectomia. O ovário esquerdo apresentava-se aumentado de volume (4 x 3 x 2cm), firme e esbranquiçado. Histologicamente havia grande número de cristais de colesterol, com acúmulo de macrófagos e algumas células gigantes multinucleadas. A lesão resultou em compressão do córtex ovariano adjacente que não continha nenhuma estrutura funcional, como folículos e corpo lúteo. O ovário contralateral não apresentava nenhuma alteração e continha múltiplos corpos lúteos.

Computed tomography-guided brain biopsy for in vivo diagnosis of a cholesterinic granuloma in a horse.

CASE DESCRIPTION: An 8-year-old warmblood mare was evaluated following an acute onset of neurologic abnormalities. CLINICAL FINDINGS: Computed tomography of the head revealed large masses in both lateral ventricles, and a presumptive diagnosis of cholesterinic granuloma was made. TREATMENT AND OUTCOME: Freehand biopsy of the intracranial masses was performed under computed tomographic guidance, and histologic examination of biopsy specimens confirmed the diagnosis. No adverse effects associated with the brain biopsy procedure were encountered. Clinical signs resolved, and long-term follow-up did not reveal any recurrence of neurologic deficits. The horse was able to return to its previous level of training. CLINICAL RELEVANCE: Findings suggested that computed tomographic-guided brain biopsy is feasible in horses and can be used to establish a diagnosis in horses with intracranial masses.

Gerbilline cholesteatoma development Part III. Increased proliferation index of basal keratinocytes of the tympanic membrane and external ear canal.

OBJECTIVE: To quantify the rate of basal cell division for keratinizing epithelium (KE) of the tympanic membrane (TM) and external ear canal (EAC) in spontaneous and induced gerbilline cholesteatomas. STUDY DESIGN AND SETTING: Cholesteatomas (3 spontaneous and 5 by induction) were labeled with tritiated thymidine for autoradiography and a KE proliferation index (PI) was determined. The PI was defined as the average number of labeled cells/mm overall and per anatomic region. RESULTS: For all regions combined, the PI was 27.3 in ears with cholesteatoma and 4.1 in normal ears (P < 0.0001). Additionally, there were significant regional differences in the PI in both normal ears and ears with cholesteatoma. CONCLUSION: The KE of cholesteatomas in gerbils proliferates at approximately 7 times the rate measured in control ears. SIGNIFICANCE: Hyperproliferation of keratinocytes is a causative factor in the development and progression of spontaneous and experimental cholesteatomas in gerbils.

Computed tomography of cholesterinic granulomas in the choroid plexus of horses.

Cholesterinic granulomas are tumor-like masses in the choroid plexuses of horses. This report describes the computed tomographic findings in four horses with cholesterinic granulomas, including the clinical and the pathologic features. All four horses had bilateral cholesterinic granulomas in the lateral ventricles. Computed tomographic images clearly delineated the masses, the opacity of the granulomas, and the enhancement pattern after intravenous bolus injection of contrast medium; these factors varied considerably. Additional CT findings were symmetric or asymmetric widening of the lateral ventricles.

Inflammatory middle ear disease of the dog: the clinical and pathological features of cholesteatoma, a complication of otitis media.

During a study of inflammatory middle ear disease in the dog cholesteatoma was found to accompany otitis media in seven of the 62 ears examined (11 per cent). The clinical, radiological and pathological findings in these animals imply that cholesteatoma in the dog is an aggressive lesion which must be differentiated from uncomplicated otitis media.

Otic cholesteatoma in the sand rat (Psammomys obesus).

To improve treatment of otic cholesteatoma, a model is needed for conduction of experiments. In the search for such a model, we have found cholesteatoma to occur naturally in Psammomys obesus. We present these findings and suggest the fat sand rat as a model for investigating cholesteatoma.

Neoplasms of Equidae.

In a retrospective study of neoplasms in Equidae pre;ented to the Animal Disease Diagnostic Laboratory, Purdue University, from Jan 1, 1970, to Dec 31, 1974, data were compiled on numbers and anatomic sites of neoplasms as well as on age, sex, and breed of subjects from which the neoplasms were taken. During this 5-year period, 21 neoplasms were diagnosed from 687 equine necropsies (3.1%) and 215 from 635 biopsies (33.9%), totaling 236 neoplasms from 1,322 cases (17.9%). The most common neoplasms were sarcoids (43.6%) and squamous cell carcinomas (24.6%). Papillomas (5.5%), nerve sheath tumors (4.2%), melanomas (3.8%), lipomas (3.0%), granulosa cell tumors (2.5%), fibromas (2.1%), cholesteatomas (1.3%), and lymphosarcomas (1.3%) were less common.