Abstract
Light microscopic and electron microscopic observations were carried out with 18 specimens of laryngeal polyp in order to elucidate pathology in the ultra structure of the polyp and discuss the etiology of the vocal cord polyp. Seven normal human vocal cords were also studied as a control. The results are as follows:
I. Normal
1) The normal lamina propria mucosae can be divided into three layers histologically: the superficial layer, the intermediate layer, and the deep layer.
2) The superficial layer is abundant in capillaries compared with the others. Within the superficial layer, there are two types of capillaries: capillaries with pores found in the area closer to the epithelium, where as in the area closer to the deeper structures, there are capillaries without pores.
II. Vocal cord polyp
1) Distribution of the capillaries with and without pores is identical to that in the normal.
2) In the area of the superficial layer closer to the vocal ligament, endothelial cells of the capillaries are thin, and the basement membrane is also thin and uncontinuous. Some capillaries without pores are ruptured.
3) Fibrin, erythrocytes and fibroblastes, which are not found in the normal lamina propria mucosae, are often observed abundantly in the deep area of the superficial layer in vocal cord polyp.
4) From the results described above, it appeares that ruptures of the capillaries without pore in the deep area of the superficial layer of the lamina propria mucosae are closely related to the cause and the growth of vocal cord polyp.
