Kryvenko, Williamson, Netto Survival Guide to Kidney and Bladder

The urinary bladder and kidney are somewhat unique organs in surgical pathology, with a wide variety of histologic patterns that are not identical to those of any other organ system. The bladder is known for both benign processes that may be difficult to distinguish from neoplasia and, conversely, neoplasms that are deceptively benign or mimic other processes.

Management of bladder tumors differs significantly based on the histologic grade and extent of invasion, and diagnosis of neoplasia typically triggers long-term follow-up and diagnostic procedures. Thus, we hope to make the most accurate diagnoses possible for patients with bladder lesions. In the kidney, recent work has discerned multiple distinct histologic tumor types from their long-established counterparts, which appear to have recurring patterns of distinct immunohistochemistry and genetics. This may lead to concern that diagnosing kidney tumors is too complicated for the surgical pathologist. However, with understanding of a few simple pattern-based approaches, we believe that the vast majority of kidney tumors can be readily diagnosed without esoteric tests. Additionally, invasion patterns in renal cell cancer are different than those in most other tumors, with tentacular outpouchings into blood vessels being more common than direct infiltration with desmoplasia.

In this survival guide, we simplify the diagnostic process for pathology of the urinary bladder and kidney, streamlining pathology evaluation to focus on the most relevant diagnostic features and most effective ancillary markers, with emphasis on diagnoses that have the greatest clinical relevance. This includes tumor diagnoses that may trigger radical therapy, benign diagnoses that, if missed, could trigger over-treatment, and diagnoses that carry strong implications for hereditary syndromes. Even for the most cutting-edge diagnoses, the tried-and-true hematoxylin and eosin-stained slide continues to demonstrate many major clues to advanced diagnoses, if not being entirely diagnostic on its own.

This atlas contains numerous illustrations of entities and scenarios that we find to be most relevant and most challenging in practice, accompanied by a focused text-based discussion and tables illustrating differential diagnoses and key features. This survival guide contains helpful information for navigating the practice of urinary bladder and kidney pathology, two organs that we consider to be among the most interesting in surgical pathology.