Morphological diagnosis of urothelial neoplasms.

The morphological classification and diagnosis of bladder neoplasms is summarised, with specific focus on histological typing, grading and staging. Four diagnostic categories are described on the basis of the pattern of growth of the urothelial lesions and tumours (flat, exophytic or papillary, endophytic, and invasive). The WHO 2004 classification is currently used. However, the WHO 1973 classification is still considered by many urologists and oncologists as the international standard in patient management.