Histologic Variants of Urothelial Carcinoma With increasing experience with urothelial carcinomas at the light microscopic level, the spectrum of microscopic forms of urothelial carcinoma has been expanded to include several…

Urinary Tract Cytopathology Christopher J. VandenBussche Syed Z. Ali George Papanicolaou demonstrated the usefulness of examining urinary sediment smears to diagnose urinary tract cancers in 1945; today, urinary tract (urinary…

Miscellaneous Nontumors and Tumors NONTUMORS Amyloidosis The bladder may be involved in cases of systemic amyloidosis but rarely is the primary site of this disease (1). The usual clinical presentation…

Secondary Tumors of The Bladder The bladder may be involved secondarily by tumors from adjacent sites such as the prostate, seminal vesicles, lower intestinal tract, and the female genital tract…

Invasive Urothelial Carcinoma Invasion in urothelial carcinoma may arise at the base of a papillary neoplasm (Ta) or within it. It can also be seen as microinvasive or invasive disease…

Papillary Urothelial Neoplasms and Their Precursors The World Health Organization (WHO)/International Society of Urological Pathologists (ISUP) classification of noninvasive papillary urothelial lesions is outlined in Table 3.1 (1). The diagnosis…

Squamous Lesions SQUAMOUS METAPLASIA Squamous epithelium, particularly in the area of the trigone, is a common finding in women (Fig. 9.1) (also see Chapter 1). Trigonal squamous epithelium in women…

Flat Urothelial Lesions There are four main reasons a surgical pathologist is asked to evaluate flat (cystoscopically apparent or unapparent) lesions. The first two indications involve multiple random biopsies by…

Urothelial Neoplasms With Inverted Growth Patterns INVERTED UROTHELIAL PAPILLOMA This is a benign tumor of the urinary bladder constituting less than 1% of urothelial neoplasms. Cystoscopically, they appear as solitary,…