[Vascular reaction in tumors in the area of the head and neck].

The vascular system possesses a variety of possibilities to respond to noxious events. Particularly the "morphological reaction" can first be observed in ultrastructural changes of the endothelial cell. In the present study we report on endothelial cell reactions in various carcinomas of the head and neck (carcinoma of the auricle, carcinoma of the maxilla). It is shown that the endothelial cell develops cytoplasmatic processes projecting into the vascular lumen. Occasionally cell edemas can be observed. The use of the scanning electron microscope allows to visualize three-dimensional aspects of the excised specimen. Tumor cells, endothelial cells and erythrocytes are obviously mixed, so that a regular vascular lumen can be found within the tumor tissue only occasionally. The results are compared and discussed, basing on available references.