Amazon.com description: Product Description: This text reflects the revised WHO classification and terminology. One major change is in the introduction of a new category: papillary urothelial neoplasm of low malignant potential. Many of the tumours previously designated as papillary transitional cell carcinoma, grade I now fall into that category. Another major change is in the designation of flat lesions, and this includes a definition of carcinoma in situ. Furthermore, a number of variant forms of urothelials carcinomas are included as well as new entities not recognized when the 1st edition was issued.