Objective. - Comment the new WHO histological classification of tumors of the urinary system and male genital organs 2016 and expose the state of art about urothelial carcinogenesis and molecular modifications of bladder cancer, with the consequences on the treatments. Material and method. - A systematic review of the literature search was performed from the data base PubMed, focused on the following keywords: "bladder cancer", "molecular", "subtypes". Results. - The new WHO histological classification of tumors of the urinary system 2016 confirm the importance of pathology in determining the care of patients, especially the grade, the histological type and the infiltration, while taking into account the difficulties. In 2014, the Cancer Genome Atlas reported genetic modifications of bladder cancer. Recently, several studies explored molecular anomalies of bladder cancer and elaborated molecular classifications, analyzing their predictive value. According to the groups, different molecular subtype had been defined: Urobasal A, Urobasal B, genomically unstable, infiltrated, squamous cell carcinoma-like and p53-like luminal bladder cancers. This latter subgroup seems to be chemoresistant. Conclusions. - The molecular biology and classifications allow a better understanding of bladder cancer and could complete in near future histological data to improve patient management. (C) 2016 Elsevier Masson SAS. All rights reserved.