Abstract and Introduction
The International Consultations on Urological Diseases are international consensus meetings, supported by the World Health Organization and the Union Internationale Contre le Cancer, which have occurred since 1981. Each consultation has the goal of convening experts to review data and provide evidence-based recommendations to improve practice. In 2012, the selected subject was bladder cancer, a disease which remains a major public health problem with little improvement in many years. The proceedings of the 2nd International Consultation on Bladder Cancer, which included a 'Pathology of Bladder Cancer Work Group,' have recently been published; herein, we provide a summary of developments and consensus relevant to the practicing pathologist. Although the published proceedings have tackled a comprehensive set of issues regarding the pathology of bladder cancer, this update summarizes the recommendations regarding selected issues for the practicing pathologist. These include guidelines for classification and grading of urothelial neoplasia, with particular emphasis on the approach to inverted lesions, the handling of incipient papillary lesions frequently seen during surveillance of bladder cancer patients, descriptions of newer variants, and terminology for urine cytology reporting.
The International Consultation on Urological Diseases (ICUD) is a World Health Organization (WHO)-registered non-governmental organization promoting improvements in world health through sponsorship and organization of interdisciplinary international consultations on the diagnosis, classification, and management of urologic diseases, with emphasis on provision of evidence-based recommendations. Prior consultations have spanned the spectrum of neoplastic and non-neoplastic urologic diseases ranging from benign prostatic hyperplasia and erectile dysfunction to prostate and bladder cancer. Bladder cancer was previously addressed in 2004 in the 1st International Consultation on Bladder Tumors in Hawaii with proceedings published in 2005. In March 2011 in Vienna, Austria, bladder cancer was revisited in the 2nd International Consultation on Bladder Cancer to provide an updated consensus and recommendations. This meeting, co-sponsored by the European Association of Urology, included a Pathology of Bladder Cancer Work Group composed of nearly 40 experts in urological pathology among a total of 10 committees formulated to address key clinical and public health questions. The 2nd Consultation on Bladder Cancer resulted in recent publication of the book, Bladder Cancer, reporting the consultation's proceedings, as well as a number of summary papers.[3–7] From the standpoint of bladder cancer pathology, this consultation, auspiciously occurring a number of years after the discussion in 1997–1998, introduction, modification, and formal WHO adoption in 2004 of the International Society of Urologic Pathology (ISUP) classification and grading system for urothelial neoplasms of the urinary bladder, offered the opportunity to examine the state of the art and begin to address a number of key questions regarding bladder cancer pathology and the pathologist's diagnostic approach.
As new findings and better data have become available about important areas of recurrent interest since the 2004 Blue Book, the proceedings of this bladder cancer pathology committee and working group provide guidance on a number of areas of value to practicing pathologists. The consultation's proceedings are publicly available in toto in electronic and print form and provide a compendium of the state of the art for this disease; the pathology section proceedings alone number >100 pages with >700 references. In particular, sections describing the microanatomy of the bladder and normal, reactive, and metaplastic epithelial changes provide a useful review, as does the review of the use of immunohistochemistry. However, as these proceedings have seen relatively limited coverage in the mainstream pathology literature, herein we have endeavored to distill a 'high yield' review of selected topics of the proceedings most relevant to the practice of urologic surgical pathology. Specifically, we cover four areas of the ICUD's recommendations: (i) the classification and grading of urothelial neoplasia with a focus on application of the grading system in routine practice, including for neoplasms with inverted morphology or those with grade heterogeneity; (ii) the diagnostic approach for incipient lesions, often seen in patients under surveillance for urothelial neoplasia, which are not accurately classifiable as per the current schema; (iii) an update on the variants of urothelial carcinoma, particularly from the perspective of newer variants or established variants with increased understanding of clinical significance; and (iv) a consensus language for urine cytology. These key offerings of the ICUD proceedings are bulleted in Summary Box 1.
Mod Pathol. 2015;28(5):612-630. © 2015 Nature Publishing Group