[429] Correlation of FISH with Atypical Urine Cytology and Its Progression to Malignancy

Julianne M Ubago, Eva M Wojcik, Guliz A Barkan. Loyola University Medical Center, Maywood, IL; Northwestern Memorial Hospital, Chicago, IL

Background: Fluorescent in situ hybridization (FISH) has been argued as a possible replacement for urine cytology to improve means of diagnosing new and recurrent urothelial carcinoma. In this study, we compiled the results of multicolor FISH tests performed on specimens diagnosed as "atypical urothelial cells" to determine the potential of FISH in identifying underlying malignancy when cytology specimens were diagnosed as atypical.
Design: From January 2008 to December 2010, all atypical urine cytology specimens at our institution were sent for FISH analysis to determine aneuploidy on chromosomes 3, 7, 17 or deletion on 9p21. We recorded and analyzed all completed FISH results to determine the sensitivity and specificity of these markers by correlating them with positive cytology and surgical pathology follow-up through June 2011.
Results: A total of 251 atypical urine cytology specimens were analyzed for FISH over three years and 22% (55/196) had positive FISH results. When comparing FISH results on atypical cytology with follow-up malignant diagnoses on cytology and surgical pathology specimens through June 2011, we found there were 23 true positives (TP), 32 false positives (FP), 177 true negatives (TN), and 19 false negatives (FN). Thus there was a sensitivity of 54.8% and a specificity of 84.7%. The positive predictive value (PPV) was 41.8% and the negative predictive value (NPV) was 90.3%.

Cytology/Histology Diagnosis Concurrence with FISH Results
 Specimen PositiveSpecimen Negative
FISH Positive2332
FISH Negative19177

Furthermore, when comparing high-grade (HG) and low-grade carcinoma (LG) results, we found that of the true positives, 13 were HG and 6 were LG. There was also 1 renal cell carcinoma, and 3 positive cytology results with no histologic follow-up. Of the false negatives, there were 8 HG and 8 LG while 3 others showed positive cytology with no histologic follow-up.
Conclusions: Our FISH statistical results are similar to recently published studies that have evaluated the sensitivity and specificity for detecting malignancy in urinary specimens. The difference in our study is that we chose to focus exclusively on atypical urine cytology. While FISH results are able to detect true urothelial carcinoma in some cases, based on our data we do not believe it is a replacement for cytologic analysis. Rather, FISH may be used as an adjunct to urine cytology in certain situations.
Category: Cytopathology

Tuesday, March 5, 2013 11:15 AM

Proffered Papers: Section F, Tuesday Morning


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