本文用透射电镜观察了44例荨麻疹的皮损和胃粘膜中肥大细胞的超微结构。肥大细胞一般呈卵圆形或不规则形,大小不等约为10～30μm。肥大细胞有伪足样胞质突起,有的突起可长达20μm。胞质内肥大细胞颗粒呈圆形或椭圆形,每个颗粒直径约0.2～0.4μm,另外胞质中可见大小不等的空泡。皮损和胃粘膜中的肥大细胞形态未见明显差异。对荨麻疹中的肥大细胞超微结构改变及其临床意义进行了初步探讨。 Transmission electron microscopy was used to observe the ultrastructural changes of mast cells in 44 cases of urticaria and gastric mucosa. Mast cells are generally ovoid or irregular in shape, ranging in size from about 10 to 30 μm. Mast cells have pseudopod-like cytoplasmic processes, some of which can be as long as 20 μm. The cytoplasmic mast cells are round or oval in shape. Each particle has a diameter of about 0.2-0.4 μm. In addition, vacuoles with different sizes can be seen in the cytoplasm. There was no significant difference in mast cell morphology between lesions and gastric mucosa. The ultrastructural changes of mast cells in urticaria and its clinical significance were discussed.