Pathological evaluation of bladder cancer typically reveals great tumour heterogeneity, and therefore the common observation of urothelial carcinoma exhibiting a wide variety of histopathological patterns is not surprising. Some of these patterns are so distinctive that they have been recognised as specific variants of urothelial carcinoma. Classifications have recently been revised in the 2016 World Health Organisation (WHO) classification of tumours of the urinary system and male genital organs. The current WHO classifications clarify terminological issues and provide better definition criteria, but also incorporate some new entities. Many of these variants have important prognostic or therapeutic implications worth knowing by the urologist and oncologist, but also represent diagnostic challenges in daily pathology practice. This review will discuss the features of variants of urothelial carcinoma in the context of our current clinical practice. Histological variations and new entities of bladder cancer not included in the current WHO classification of urothelial tumours will be briefly discussed.
Histopathology. 2019 Jan [Epub]
Antonio Lopez-Beltran, Vanessa Henriques, Rodolfo Montironi, Alessia Cimadamore, Maria R Raspollini, Liang Cheng
Department of Pathology and Surgery, Faculty of Medicine, Cordoba, Spain., Pathology Service, Champalimaud Clinical Center, Lisbon, Portugal., Section of Pathological Anatomy, Polytechnic University of the Marche Region, School of Medicine, Ancona, Italy., Histopathology and Molecular Diagnostics, University Hospital Careggi, Florence, Italy., Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.