胆脂瘤上皮过度增殖行为的免疫组化研究

目的 探讨中耳胆脂瘤上皮的过度增殖性和生长方式。方法 用免疫组化SP法观察了表皮生长因子受体（epidermal growth factor receptor,EGFR），增殖细胞核抗原Ki67、Ⅳ型胶原蛋白（collagenⅣ）和层粘连蛋白（laminin,LN）在18例胆脂瘤标本的表达，并与8例外耳道正常皮肤相比较。结果 EGFR有两种染色图案，棕黄色的线状或颗粒状细胞膜强染色和颗粒状的胞浆染色，胆脂瘤标本染色均强于皮肤。在Ki67的免疫染色中，阳性细胞核为棕黄色，胆脂瘤上皮的阳性细胞核比皮肤多。CollagenIV和LN图案极其相似，为连续的宗黄色线状和（或）带状图案。4例胆脂瘤上皮基膜下结膀组织中的血管比皮肤丰富。结论 EGFR和Ki67在胆脂瘤上皮的表达从不同角度反映了胆脂瘤上皮的过度增殖性。CollagenIV和LN的表达说明胆脂瘤属良性病变，血液供应可能比皮肤丰富。

Immunohistochemical study of the epithelial hyperproliferation in middle ear cholesteatoma]

OBJECTIVE: To elucidate the role of epidermal growth factor (EGF) in the growth of cholesteatoma, and to investigate the biological behaviour of cholesteatoma. METHODS: The expression of EGF receptor (EGFR), proliferating cell nuclear antigen Ki-67, collagen IV protein and laminin in 18 specimens of cholesteatoma was stained immunohistochemically and compared with that in epidermis of 8 specimens of normal external auditory meatus skin. RESULTS: The immunostaining for EGFR showed two patterns: strong linear or granular cell surface staining and granular cytoplasmic staining. In epidermis of normal skin, EGFR appear to be highly expressed on the basal layer. Cholesteatoma epithelium showed increased positive reactions in the super basal layers. The Ki67 was expressed in nuclei, and a dot-like as well as a diffuse nuclear staining pattern was detected. The Ki67 expression was restricted in the basal layer of normal epithelium, and the positive of Ki67 in nuclei was rare. The expression of Ki67 in cholesteatoma extended to the suprabasal and upper layers of the epithelium with an increasing frequency of positive cells. Collagen IV and Laminin were similary localized in the basement membrane of normal epithelium with a continuously staining pattern and a similar staining pattern was also found in the cholesteatoma, and the vas is abundant under basement membrane in some cholesteatoma samples. CONCLUSION: The overexpression of EGFR suggest a hyperproliferative state in cholesteatoma and there is a close relationship between the EGF and hyperproliferation of cholesteatoma. The increased expression of Ki67 confirms the hyperproliferative nature of cholesteatoma. The results of expression of Collagen IV and Laminin in cholesteatoma indicate it is a benign disease.