Comparison of biopsy devices in upper tract urothelial carcinoma

Abstract

Introduction: A correct characterization of upper tract urothelial carcinoma (UTUC) lesions is fundamental to appropriately select patients suitable for endoscopic management. We analyzed the diagnostic yield of three different biopsy tools for the histology evaluation of the UTUC. Furthermore, the concordance between biopsy grading and final UTUC pathology results at specimen (i.e., after ureterectomy or radical nephroureterectomy-RNU) was evaluated.

Materials and methods: Three different devices were evaluated: 3F biopsy forceps, 6F BIGopsy^® Backloading biopsy forceps and the 2.2F Nitinol Basket. Data were collected between January 2015 and October 2017 and retrospectively analyzed. Univariate and multivariate logistic regression analyses were performed to identify the variables related to diagnosis.

Results: A total of 302 biopsies were taken: lesions could be characterized in 236 (78.2%) specimens by the pathologist. Positive biopsies for UTUC were found in 140 specimens. In 66 biopsies (21.8%), the quality of the tissue sampled was inadequate for a histological characterization; of these, 55 (83.3%) were taken using 3F forceps and 11 (16.7%) using BIGopsy forceps. No inadequate specimen arose using the 2.2F Nitinol Basket. Among 28 patients who underwent distal ureterectomy or RNU, the tumor was upgraded to high grade in 9 (32%), while in 19 (68%) the grading was confirmed.

Conclusion: In comparison to 3F forceps, the BIGopsy forceps showed to be more accurate in obtaining sufficient specimen for pathologic examination. In papillary lesions, the 2.2F Nitinol basket achieves a final histology characterization in 100% of the cases. For tumor < 2 cm, there is a high concordance between URS biopsy grade and final pathology (distal ureterectomy or RNU).

Keywords: Biopsy; Flexible ureteroscopy; Nephro-sparing surgery; Upper tract urothelial carcinoma.