Urinary Tract Biopsy Correlates Urothelial Carcinoma Diagnosis

Urothelial carcinoma (UCC), also known as transitional cell carcinoma (TCC) is a type of cancer that typically occurs in the urinary system. It is the most common type of bladder cancer and cancer of the ureter.

UCC is the second most common type of kidney cancer, but accounts for only five to 10% of all primary renal malignant tumors. UCC arises from the transitional epithelium, a tissue lining the inner surface of these hollow organs. Transitional cell carcinoma (TCC) accounts for more than 95% of urothelial tumors of the upper urinary tract.

Scientists at the University of Chicago (Chicago, IL, USA) searched their Department of Pathology archive for all cases of upper urothelial tract biopsies and washings between the years 2005 and 2015 that had nephroureterectomy for urothelial carcinoma. In all, 126 patients met the inclusion criteria. They considered cytology diagnoses of either urothelial cancer or “suspicious for urothelial cancer” to be positive. They compared the concordance between combined biopsy and washing, and then compared biopsy and washing diagnoses with the presence of carcinoma on resection.

The team found that from the 126 patients who had resection, only 72 patients had prior diagnostic material. Of those, 33 (26%) had combined biopsy and washing, 26 (21%) had biopsy only, and 13 (10%) had washing only. Among the patients who had had both procedures, 15 (45%) of the diagnoses were concordant as indicated by positive biopsy and cytology, and the final resection specimen revealed urothelial carcinoma. One patient, who was considered concordant, had negative results for both procedures but had urothelial carcinoma on resection.

The scientists found that among the 17 discordant combined biopsy and cytology cases, 11 had positive biopsy with negative washing, four had negative biopsy with positive washing and for two cases, neither biopsy nor washing was diagnostic. Among the 11 positive biopsies with negative washing, five were low-grade papillary urothelial cancer, four were high-grade papillary urothelial cancer, one was urothelial cancer in situ, and one was high-grade urothelial cancer suspicious for invasion.

Providers often obtain biopsies and cytology washings of the upper urinary tract to help them diagnose urothelial cancer, but may have only one procedure performed. Shiraz Fidai, MD, and Tatjana Antic, MD, co-authors of the study, said, “Overall, based on our data, both biopsies and washings of the upper tract (83% for biopsies and 59% for washings) are appropriate in diagnosing urothelial cancer. However, biopsies are more suitable for diagnosing low-grade papillary urothelial cancer when compared with cytology. Size and multifocality of the urothelial cancer of the upper urinary tract plays a significant role in obtaining an adequate specimen for either diagnosis or grading.” The study was presented at the Annual Meeting of the American Society for Clinical Pathology (ASCP), held September 6-8, 2017, in Chicago, IL, USA.

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