[Mast cells in the labial cancer: histochemical and electron microscopical study].

The labial cancer tissue of 24 cases and normal labial tissue of 7 cases were studied histochemically and electron microscopically. The result showed that the number of mast cells around the periphery of labial cancer tissue increased significantly. The histochemical properties of these mast cells differed from those in the normal labial tissue. The former did not contain heparin which was present normally. Under electron microscope, according to the characteristic ultrastructure, the mast cells around the labial cancer were TC mast cells. Some of them showed the appearance of degranulation, and contacted intimately with cancer cells, lymphocytes and macrophages, etc. These findings suggest that together with lymphocytes, macrophages, these mast cells contribute to the defence reaction to the cancer tissue.