Urothelium normally consists of 4 to 6 layers of cells. The uppermost layer consists of umbrella cells (not well seen in this image) which may hae irregular hyperchromatic nuclei.

• 正常膀胱上皮含有4-6层上皮细胞。最浅表的一层里包括伞状细胞，细胞核呈不规则深染。