[Role of perimatrix fibroblasts in development of acquired middle ear cholesteatoma. A hypothesis].
ABSTRACT The epithelial pathogenesis of acquired cholesteatoma has been widely accepted, but clinical and experimental data have not been able to answer questions like: How does a cholesteatoma start or grow or how is bone resorption of conducted? From our own experiments and literature a new hypothesis of cholesteatoma origin and growth is drawn. Three prerequisites are necessary for development: (1) the unique anatomical situation at the ear-drum (two different epithelial layers close together); (2) chronic destruction of the submucosal tissue in the middle ear (infection, inflammation); (3) wound healing (proliferation phase). Destruction of the submucosal space by middle ear infection and cell necrosis starts the wound healing cascade. In wound healing generally the connective tissue fibroblasts and macrophages play a pivotal role. Cytokines of the wound healing thought to promote the re-epithelization of the mucosal defect and scar tissue development act upon the intact squamous cell layer of the outer surface of the ear-drum at the same time. Thereby a proliferation of the undamaged epithelial layer is induced. Cholesteatoma matrix is always surrounded by a layer of connective tissue, the perimatrix. Persistence of the inflammation causes permanent wound healing in the perimatrix, proliferation of the fibroblasts (granulation tissue) and proliferation of the epithelium (matrix). It is speculated that by virtue of wound healing cytokines of fibroblasts and macrophages are the driving forces of cholesteatoma origin, growth and bone destruction.
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ABSTRACT: Authors debate about cholesteatomas, from the first time this word was employed, by Muller, in 1838, until the recent updates. They dissert about its definition, etiology and pathology and present basic concepts about its biology. They also make a wide review about pediatric cholesteatoma, its epidemiology and biology, and compare it with adult cholesteatoma. Finally, they describe some articles about ossicle chain erosion and its correlation with cholesteatoma perimatrix, collagen and collagenase.Brazilian journal of otorhinolaryngology 08/2005; 71(4):536-45. · 0.62 Impact Factor
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ABSTRACT: Cholesteatoma is constituted of matrix, perimatrix and cystic content. Some authors affirm that, in children, its clinical behavior is more aggressive of the than in adults. Histologic compared cholesteatomas of children and adults. 74 cholesteatomas been analyzed, being 35 of pediatrics patients (<18 years). The average number of cellular layers and hyperplasia in the matrix had been evaluated; thickness, delimitante epithelium, fibrosis, inflammation and granuloma in the perimatrix. The analysis statistics was carried through with program SPSS 10.0, using the coefficients of Pearson and Spearman, test of chi-square and t test. The number of cellular layers in the matrix was of 8.2+/-4.2. The hyperplasia appears in 17%, fibrosis in 65%, granuloma in 12% and the delimitante epithelium in 21%. The perimatrix presented a medium one of 80 micrometers (37 the 232), minimum value zero and maximum value 1.926. The histological degree of inflammation was considered of moderate the accented one in 60%. When applying the coefficient of Spearman enters the inflammation degree and average of cellular layers of the matrix with the variables of the measure of thickness of the perimatrix we find correlations, significant, with moderate magnitudes of the great ones (rs=0.5 and P<0.0001). Adults colesteatomas of and child had not been identified to morphologic differences between. We find correlation enters the intensity of the inflammation and of the average of cellular layers of the matrix with the thickness of the perimatrix, what it can predict its aggressiveness, more studies are necessary to define the paper of this finding in pathogenesis of cholesteatoma.Brazilian journal of otorhinolaryngology 10/2006; 72(5):641-8. · 0.62 Impact Factor
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ABSTRACT: Cholesteatoma may occur either in children as in adults; in children, however, they have a more aggressive and extensive growth. OBJECTIVE: To compare the thickness of the perimatrix, in microm, between adults (>18 years old) and children cholesteatomas. STUDY DESIGN: transversal cohort. MATERIAL AND METHOD: 74 cholesteatomas (35 of children) obtained from othologic surgeries were included, fixed in formol 10%. It was made laminas with HE and Picrossisius, with were studied at the optic microscope. We obtained digital images of the laminas at the Image Pro-Plus and we used Spearman's coefficient for data analysis. Differences were considered statistically significant if P.Brazilian journal of otorhinolaryngology 12/2005; 71(6):792-7. · 0.62 Impact Factor