A Novel Technique to Improve the Processing of Minute Ureteroscopic Biopsies.

To examine the ability of a new specimen handling technique to improve histopathological yield of ureteroscopic biopsies, performed in patients with suspected upper tract urothelial carcinoma (UTUC). In a bi-center retrospective study we compared the results of the new tissue handling technique (group 1) with the standard technique (group 2). In the new technique, to achieve maximal tissue preservation, the specimen is mounted on filter paper prior to embedding in paraffin. Multivariate analysis was performed to determine which factors are associated with optimal histological results. We further compared the biopsies with the final specimen in a subgroup of patients who underwent nephroureterectomy (NU). Of 55 ureteroscopic biopsies, 1 biopsy from group 1 (new technique) and 3 biopsies from group 2 (standard technique) were inadequate for pathological examination. 51 UTUC specimens were analyzed. Tumor grade and stage were determined in 85% and 63% of the patients in group 1 and in 83% and 25% of group 2 (p=0.85 and p=0.007). Orientation was preserved in 82% of group 1 and 42% of group 2 (p=0.003). On multivariate analysis biopsy technique and biopsy diameter were found to predict stage determination (p=0.01 and p=0.007) and tissue orientation (p=0.005 and p=0.04). Among patients who underwent NU, stage concordance between the biopsy and final pathology was observed in 56% and 27% of the patients in group 1 and 2, respectively. The new processing technique for small UTUC forceps biopsies decreases the rate of biopsies with insufficient material and improves biopsy interpretation.