Mieke Bus

12 Chapter 1 This treatment can only be applied without compromising survival rates, in a strictly selected patient group with low-grade, non-invasive disease who is able to undergo a stringent sur- veillance following treatment, since conservative treatment is at risk of recurrences and progression. 1 For tumour classification both tumour stage and tumour grade will be assessed by the pathologist. Table 1: Tumourclassification (T-stage) of ureter and pyelumtumours according the TNM classification system of the UICC (2009). stage ureter pyelum Tx Primary tumour cannot be assessed Primary tumour cannot be assessed T0 No evidence of primary tumour No evidence of primary tumour Ta Non-invasive papillary tumour Non-invasive papillary tumour Tis carcinoma in situ carcinoma in situ T1 tumour invades lamina propria tumour invades lamina propria T2 tumour invades muscularis propria tumour invades muscularis propria T3 tumour invades beyond muscularis into periureteral fat tumour invades beyond muscularis into peripelvic fat or renal parenchyma T4 tumour invades adjacent organs tumour through the kidney into perinephric fat or adjacents organs UICC = Union for International Cancer Control. The TNM classification of the Union for International Cancer Control (UICC) is currently the most used system for staging of upper urinary tract tumours (Table 1). For tumour grading two systems exist, the system of the World Health Organisation (WHO) dating from 1973 and the system dating from 2004 of theWHO and International Society of Urological Pathology (ISUP). What are the challenges in UTUC? Now endoscopic treatment using ureterorenoscopy has been recognized as a kidney spar- ing treatment of low risk UTUC, knowledge of tumour stage and grade is needed for clinical decision making to decide which patients are eligible for endoscopic treatment. 6  Overall consensus is that this technique can only be applied in patients with low-grade and low stage disease. 1 However, adequate identification and diagnosis of all UTUC lesions is chal- lenging with the available diagnostic methods. One of the main challenges in patient selec- tion for endoscopic treatment of UTUC is to obtain a reliable histopathological diagnosis.  Unfortunately, current methods to obtain histopathological diagnosis are limited. Biopsy specimens retrieved during ureterorenoscopy are frequently minute, because of the