Diagnostic accuracy of upper tract urothelial carcinoma: how samples are collected matters.

OBJECTIVES

The aims of this study were to determine the accuracy and reliability of cytology, histopathology and ploidy of specimens obtained at ureterorenoscopy, to evaluate the importance of how samples are collected and to determine whether cytology is an alternative to histology of biopsies.

METHODS

This prospective study investigated the accuracy of grading of endoscopically taken cytology and histopathology samples from 45 consecutive patients by comparing these with subsequent nephroureterectomy specimens. Histopathology grading was done according to WHO 1999 and 2004 classifications. Ploidy was determined using photospectrometry.

RESULTS

Forty-five patients were included. Both cytology and histopathology identified almost all cancers (91% and 94%, respectively) in collected samples. In cytology as well as in histopathology, agreement in grade between barbotage and nephroureterectomy specimens was statistically significant for both 1999 and 2004 WHO classifications. All cancers in the endoscopic biopsies were identified as pathological, although the grading was not correct in all cases. A statistically significant correlation was found between grade and ploidy in grade 1 and grade 3 nephroureterectomy specimens.

CONCLUSIONS

Specimens collected at ureterorenoscopy (biopsies for histology, barbotages for cytology and analysis of ploidy) proved to be relevant and useful. Barbotage cytology identified 91% of all cancers, a high rate compared to techniques used in other studies, and was also sensitive in detecting low-grade tumours. Barbotage cytology and biopsy histology were equally efficient in detecting cancer. The authors recommend that both barbotage and biopsy be performed in addition to complete ureterorenoscopy. Moreover, if there is no visible lesion, cytology is the only reliable option.