Mieke Bus

10 Chapter 1 Urothelial carcinoma of the upper urinary tract The urinary tract is divided in the lower and upper urinary tract. The lower urinary tract encompasses the urinary bladder and the proximal urethra in females and the prostatic urethra in males. The upper urinary tract encompasses the renal calyces, pelvis and ureter. The epithelial lining of the urinary tract is called the urothelium and it is from this cell layer that urothelial carcinoma derives (figure 1). A B Figure 1: CT-urography showing contrast excretion phase. (a) axial cross-sectional imaging demonstrating a filling defect in the left pyelum, suggestive for tumour growth (red arrow). (b) the same tumour in coronal cross-sectional imaging (red arrow). Ureterorenoscopy following the CT scan demonstrated a tumour in the pyelum. Urothelial carcinoma can occur at any site of the urinary tract. Upper tract tumours are rare compared to bladder tumours. Ninety five percent of all urothelial cancers occur in the blad- der versus 5% in the upper urinary tract. Upper urinary tract urothelial carcinoma (UTUC) and urothelial carcinoma (UC) of the bladder can develop synchronously or metachronously in a multifocal way. Identified risk factors for urothelial cancer apply to both the upper uri- nary tract and lower urinary tract. However, the natural course and genetical characteristics of UTUC differ from UC of the bladder and the anatomy of the upper urinary tract requires a different approach to diagnosis and therapy compared to bladder tumours. Moreover, there are upper urinary tract specific risk factors identified for developing UTUC, underlying the different pathogenesis. 1 For these reasons UTUC cannot be considered as a bladder tumour in the upper urinary tract and should be considered as a distinct entity from bladder carci- noma. Diagnosis, treatment and follow-up should be specified to UTUC. Over the past decades, radical nephroureterectomy is considered the gold standard in the treatment of UTUC. Surgery consists of extrafascial dissection of the kidney and entire length of ureter including a bladder cuff (figure 2).