[Update on urothelial carcinoma histopathology].

Urothelial carcinoma comprise a heterogenous group of diseases with very different clinical outcome: 70%-80% of urothelial carcinoma are genetically stable and associated with a favorable prognosis, while 20%-30% are genetically unstable and have a high progression rate. Therefore, the current WHO Classification (2004) reduces the histologic grade to simply 'low grade' and 'high grade'. In addition to TNM classification and histologic grade, genetic factors such as p53 mutations, fibroblast growth factor receptor 3 (FGFR3) and phosphatidylinositol-3-kinase (PIC(3)CA) are relevant in a patient's prognosis.