Cholesteatoma and meningoencephalitis in a dog with chronic otitis externa

Abstract

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.

Clinical analysis and nonsurgical management of 11 dogs with aural cholesteatoma

“…In the present study, histopathological evaluation of external ear canal nodules in five cases revealed a core of OM. Likewise, it has been reported in a German shepherd dog with a cholesteatoma in the middle ear, accompanied by a cholesterol granuloma with a core of OM in the horizontal ear canal . OM is a type of ectopic ossification of fibrous connective tissue …”

“…In humans, early diagnosis of cholesteatoma depends on its identification with otoscopic examination . In veterinary medicine, otoscopy is used to diagnose the condition, although definitive diagnosis requires histopathological examination . Computed tomography (CT) and magnetic resonance imaging (MRI) are considered to be reliable methods for evaluating the middle ear and demonstrating middle ear‐related lesions .…”

“…To the best of the authors’ knowledge, 15 reports (covering a total of 70 cases) of canine cholesteatoma have been published . Reports in which the diagnosis of cholesteatoma was confirmed by histopathological evaluation in combination with CT and MR imaging are limited .…”

“…The only curative treatment for canine cholesteatoma reported to date is surgery with total ear canal ablationlateral bulla osteotomy (TECA-LBO) and ventral bulla osteotomy. 1,2,10,16 The prime objective of surgery for cholesteatoma is to remove all keratinous debris and stratified squamous epithelium; 17 recurrence postsurgery is common in animals. [1][2][3] To the best of the authors' knowledge, 15 reports (covering a total of 70 cases) of canine cholesteatoma have been published.…”

“…[1][2][3] To the best of the authors' knowledge, 15 reports (covering a total of 70 cases) of canine cholesteatoma have been published. [1][2][3][4][5][6][7][8]10,13,15,16,[18][19][20] Reports in which the diagnosis of cholesteatoma was confirmed by histopathological evaluation in combination with CT and MR imaging are limited. 1,8 No clinical studies of nonsurgical management for aural cholesteatoma have been reported.…”