[Histochemical and electron microscopical study on mast cells in the stroma of thyroid tumours]

To understand the number and morphology of the mast cells of throid tumours stroma, the mast cells (MCs) of 62 cases of thyroid tumour stroma were studied histochemically and electron microscopically. The number of MCs was increased significantly in thyroid tumour as compared with that in normal tissues. The number of MCs between thyroid cancer and thyroid adenoma was of no difference. When stained with Alcian Blue-Safranin, MCs in the stroma of normal thyroid were blue whereas in the stroma of thyroid tumour both blue and red mast cells could be found. The ultrastructure of the granule of the MCs was homogeneous electron-dense, which was the characteristic feature of TMCs. Degranulation of MCs adjacent to tumour cells could be seen. The significance of MCs in the stroma of thyroid tumour was discussed.