Masaki M, Wright C G, Lee D H, Meyerhoff W L
Department of Otorhinolaryngology, University of Texas Southwestern Medical School, Dallas.
Acta Otolaryngol. 1989 Jul-Aug;108(1-2):113-21. doi: 10.3109/00016488909107401.
This study was designed to investigate morphological changes in the tympanic membrane (TM) associated with cholesteatoma formation in experimental animals following application of propylene glycol to the middle ear. A 50% solution of propylene glycol was applied bilaterally to the middle ear cavities of 30 young-adult chinchillas. The animals were sacrificed for light and electron microscopic study at intervals of 2 days to 6 weeks after a single application of 0.2 ml of the propylene glycol solution. At 2 days there was complete destruction of the epidermal and mucosal layers of the TM. The denuded lateral surface rapidly became re-epithelialized by hyperplastic epidermal cells and by 2-3 weeks, keratinizing epidermis penetrated damaged areas of the fibrous layer of the lamina propria to reach the medial surface of the TM. These epidermal cells proliferated in the middle ear cavity, forming cholesteatomas. Our observations indicate that invasion of the intact, but structurally altered, tympanic membrane by hyperplastic epidermis is a primary mechanism of cholesteatoma formation in the animal model.
本研究旨在探讨在实验动物中耳应用丙二醇后，与胆脂瘤形成相关的鼓膜（TM）形态学变化。将50%的丙二醇溶液双侧应用于30只成年幼年龙猫的中耳腔。在单次应用0.2 ml丙二醇溶液后，每隔2天至6周处死动物进行光镜和电镜研究。2天时，鼓膜的表皮层和黏膜层完全破坏。裸露的外侧表面迅速被增生的表皮细胞重新上皮化，到2 - 3周时，角化表皮穿透固有层纤维层的受损区域，到达鼓膜的内侧表面。这些表皮细胞在中耳腔内增殖，形成胆脂瘤。我们的观察结果表明，增生的表皮侵入完整但结构改变的鼓膜是动物模型中胆脂瘤形成的主要机制。
