EGFR expression in acquired middle ear cholesteatoma in children and adults.

Middle ear cholesteatomas are characterized by the presence of keratinized stratified squamous epithelium inside this cavity. It is considered to be more aggressive in childhood. In normal skin, the epidermal growth factor receptor (EGFR) is expressed in the cytoplasmic membrane of epithelial cells of the basal layer. In contrast, its expression in middle ear cholesteatoma extends to suprabasal layers. The objective of this study is to detect the presence of EGFR in cases of acquired cholesteatoma of the middle ear and correlate the expression of this receptor with patients' ages. In this cross-sectional study, cholesteatoma samples were collected from 50 patients (35 adults and 15 children) who underwent otological surgery, throughout 1 year of study. These samples were subjected to histological and immunohistochemical assays. Results were submitted to statistical analyses and main findings were: EGFR was present in the parabasal layers in 27 cases and EGFR expression was extended to all layers of the matrix in 17 cases. There were no statistically significant differences in what concerns age-related variances in EGFR expression. The intensity and location of EGFR expression in acquired cholesteatoma of the middle ear confirm the hyperproliferative capacity of keratinocytes.

TNF-R2 expression in acquired middle ear cholesteatoma.

UNLABELLED: Acquired middle ear cholesteatoma is a disease which promotes bone erosion resulting in potentially serious complications. The tumor necrosis factor alpha (TNF-α) is present in cholesteatoma and it is related to bone erosion, as shown by different authors. To understand the aggressiveness characteristics of cholesteatoma is necessary, however, to better address the presence and distribution of their receptors. OBJECTIVE: To evaluate the expression of type 2 TNF-α receptor (TNF-R2) in fragments of cholesteatoma and correlate it to the degree of inflammation present. MATERIAL AND METHODS: observational cross-sectional study, which analyzed 33 fragments of cholesteatomas through histological analysis and immunohistochemistry (using as primary antibody to TNF-R2 LabVision® brand). The evaluation was performed by means of a qualitative and semi-quantitative agreement with the observed intensity. For statistical analysis we used the Fisher exact test and Spearman's correlation coefficient (considered statistically significant when p < 0. 05). RESULTS: The expression of TNF-R2 was present in all fragments, however a statistical analysis showed no correlation or association between inflammation and the expression of TNF-R2. CONCLUSIONS: TNF-R2 is present in cholesteatoma of the middle ear, however, its expression is not directly related to the degree of inflammation observed in patients with this disease.

TNF-R2 expression in acquired middle ear cholesteatoma / Expressão do TNF-R2 no colesteatoma adquirido da orelha média

Acquired middle ear cholesteatoma is a disease which promotes bone erosion resulting in potentially serious complications. The tumor necrosis factor alpha (TNF-α) is present in cholesteatoma and it is related to bone erosion, as shown by different authors. To understand the aggressiveness characteristics of cholesteatoma is necessary, however, to better address the presence and distribution of their receptors. OBJECTIVE: To evaluate the expression of type 2 TNF-α receptor (TNF-R2) in fragments of cholesteatoma and correlate it to the degree of inflammation present. MATERIAL AND METHODS: observational cross-sectional study, which analyzed 33 fragments of cholesteatomas through histological analysis and immunohistochemistry (using as primary antibody to TNF-R2 LabVision® brand). The evaluation was performed by means of a qualitative and semi-quantitative agreement with the observed intensity. For statistical analysis we used the Fisher exact test and Spearman´s correlation coefficient (considered statistically significant when p < 0. 05). RESULTS: The expression of TNF-R2 was present in all fragments, however a statistical analysis showed no correlation or association between inflammation and the expression of TNF-R2. CONCLUSIONS: TNF-R2 is present in cholesteatoma of the middle ear, however, its expression is not directly related to the degree of inflammation observed in patients with this disease.

O colesteatoma adquirido da orelha média promove erosão óssea, ocasionando complicações potencialmente graves. O fator de necrose tumoral alfa (TNF-α) está presente no colesteatoma adquirido da orelha média e relaciona-se com a erosão óssea, como demonstraram diferentes autores. Para que se compreenda as características de agressividade do colesteatoma, é necessário que se estude a presença e a distribuição seus receptores. OBJETIVO: Avaliar a expressão do receptor tipo dois do TNF-α (TNF-R2) em fragmentos de colesteatoma e relacioná-lo com o grau de inflamação. MATERIAL E MÉTODOS: Estudo observacional do tipo transversal. Foram analisados 33 fragmentos de colesteatomas, submetidos à análise histológica e imunoistoquímica (utilizando o TNF-R2 da marca Labvision®). A avaliação foi realizada de forma qualitativa e semiquantitativa, de acordo com a intensidade observada. Para a análise estatística, foram utilizados o teste exato de Fischer e o coeficiente de correlação de Spearman (estatisticamente significativo quando p < 0,05). RESULTADOS: A expressão do TNF-R2 estava presente em todos os fragmentos, entretanto a estatística não evidenciou correlação, nem associação entre o processo inflamatório e a expressão do TNF-R2. CONCLUSÕES: O TNF-R2 está presente no colesteatoma adquirido da orelha média. Entretanto, a sua expressão não está relacionada ao grau de inflamação.

Hyperproliferation markers in ear canal epidermis.

UNLABELLED: Several studies involving immunohistochemical methods to assess external auditory canal epidermis have been performed with different objectives. With this method it is possible to assess the expression of various antigens such as cytokeratins, cytokines, and hyperproliferation markers among others. AIM: to revise, describe and analyze the knowledge generated by identifiable papers published on the worldwide literature about immunohistochemical hyperproliferation markers in normal external auditory canal epidermis. MATERIALS AND METHODS: systematic review of the papers published until 2009, in indexed international journals. RESULTS: Various antigens related to hyperproliferation were investigated by immunohistochemical methods among the included papers. The most studied ones were cytokeratin 16, Ki-67 and PCNA. CONCLUSIONS: most of the studies utilized external auditory canal epidermis as control sample to study external ear or middle ear cholesteatoma with immunohistochemical methods. There is a hyperproliferative antigen concentration, such as CK16, Ki-67 and PCNA, in the annulus tympanicus, adjacent meatus and tympanic regions, mainly in the lower areas.

Marcadores de hiperproliferação na epiderme do meato acústico externo / Hyperproliferation markers in ear canal epidermis

Vários estudos envolvendo métodos imunoistoquímicos para avaliação da epiderme do meato acústico externo já foram realizados com os mais diversos objetivos. Por estes métodos é possível avaliar a expressão de antígenos como as citoqueratinas, citocinas, marcadores de hiperproliferação, entre outros. OBJETIVO: Revisar, descrever e analisar a expressão dos marcadores imunoistoquímicos de hiperproliferação na epiderme do meato acústico externo normal. MATERIAIS E MÉTODOS: Revisão sistemática de artigos publicados até o ano de 2009 em periódicos internacionais indexados. RESULTADOS: Vários antígenos relacionados à hiperproliferação foram pesquisados por meio de métodos imunoistoquímicos dentre os artigos analisados. Os mais estudados foram a citoqueratina 16, o Ki-67 e o PCNA. CONCLUSÕES: A maioria dos trabalhos utilizou fragmentos de epiderme do meato acústico externo como amostra controle para estudo imunoistoquímico do colesteatoma da orelha média ou externa. Há uma concentração de marcadores de hiperproliferação como a CK16, o Ki-67 e o PCNA no anel fibrocartilagíneo e nas regiões adjacentes do meato acústico externo e da membrana timpânica.

Several studies involving immunohistochemical methods to assess external auditory canal epidermis have been performed with different objectives. With this method it is possible to assess the expression of various antigens such as cytokeratins, cytokines, and hyperproliferation markers among others. AIM: to revise, describe and analyze the knowledge generated by identifiable papers published on the worldwide literature about immunohistochemical hyperproliferation markers in normal external auditory canal epidermis. MATERIALS AND METHODS: systematic review of the papers published until 2009, in indexed international journals. RESULTS: Various antigens related to hyperproliferation were investigated by immunohistochemical methods among the included papers. The most studied ones were cytokeratin 16, Ki-67 and PCNA. CONCLUSIONS: most of the studies utilized external auditory canal epidermis as control sample to study external ear or middle ear cholesteatoma with immunohistochemical methods. There is a hyperproliferative antigen concentration, such as CK16, Ki-67 and PCNA, in the annulus tympanicus, adjacent meatus and tympanic regions, mainly in the lower areas.