Pathogenesis of Middle Ear Cholesteatoma

Abstract

Middle ear cholesteatoma is characterized by enhanced proliferation of epithelial cells with aberrant morphological characteristics. To investigate the origin of the cholesteatoma cells, we analyzed spontaneously occurring cholesteatomas associated with a new transplantation model in Mongolian gerbils (gerbils). Cholesteatomas were induced in gerbils with a transplanted tympanic membrane by using the external auditory canal (EAC) ligation method. After the pars flaccida of the tympanic membranes were completely removed from male gerbils, corresponding portions of tympanic membranes of female gerbils were transplanted to the area of defect, and then we ligated the EAC (hybrid-model group). As a control group, the EAC of normal male and female gerbils was ligated without myringoplasty. In all ears of each group, the induced cholesteatomas were seen. In situ PCR was then performed to detect the mouse X chromosomelinked phosphoglycerate kinase-1 (pgk-1) gene on the paraffin sections. One pgk-1 spot in the epithelial nuclei was detected in male cholesteatoma, and two pgk-1 spots were detected in female cholesteatoma, respectively. On the other hand, in the hybrid-model group, we detected not only one but also two pgk-1 spots in the epithelial nuclei of cholesteatoma. These results strengthened the evidence that the origin of epithelial cells in cholesteatoma is the tympanic membrane in this model, but not the residential middle ear epithelial cells or the skin of the EAC. (Am J

Autologous Meatal Skin Graft Implantation and Intratympanic Injection of <b><i>Pseudomonas aeruginosa</i></b>: A New Experimental Mouse Model of Acquired Middle Ear Cholesteatoma

“…Finally, it took only 6 weeks for the cholesteatoma to form. This modeling time is much shorter than those reported previously [6]. Furthermore, the cholesteatoma formation was demonstrated by a CT scan and histological analysis in our study.…”

“…Technically, many modeling methods have been reported to successfully induce cholesteatoma including the ligation of the external ear canal [5,16], blocking of the eustachian tube [17,18], injection of chemical or biological material into the middle ear [19], autologous dermal implantation [2,20,21], and local hybrid ear [6]. However, in the present study we implanted autologous meatal skin grafts into the middle ear via the tympanic membrane followed by an intratympanic injection of PA to experimentally induce middle ear cholesteatoma in a mouse model.…”

“…Although the etiopathogenesis of acquired cholesteatoma is still being debated, there are at least 4 different theories for the development of this auditory disorder [6]: (1) the metaplasia theory: there is a keratinization of the squamous metaplasia of the mucosal lining of the middle ear due to a chronic infection; (2) the immigration theory: the squamous epithelium of the external auditory canal invades/immigrates through tympanic membrane perforation; (3) the hyperplasia theory: inflammation results in invasive hyperplasia of the basal cell layers of the middle ear, and (4) the retraction pocket theory: retraction pockets and invaginations of the tympanic membrane are formed due to chronic eustachian tube dysfunction. Regardless of their underlying pathogenesis, all cholesteatomas share similar properties.…”

The methods of surgical sanation of the difficult to access parts of the middle ear in the patients presenting with chronic suppurative otitis media and concomitant cholesteatoma

“…ных осложнений [1,2]. Единственным способом лечения холестеатомы является ее полное хирургическое удаление, при котором необходимо учитывать как патогенетические механизмы ее развития, так и возможные пути распространения.…”

Comparison of histopathological characteristics and clinical behavior of acquired cholesteatoma

“…Middle ear cholesteatoma is characterized by a severe inflammatory reaction that results in active destruction in tissue and bone [5,6]. Middle ear cholesteatoma can cause hearing loss and occasionally facial nerve palsy and it can recur after surgical treatment [7]. The only treatment known for cholesteatoma is tympanomastoidectomy which is done using two techniques, namely wall-down and wall-up [8].…”