Renal Tumors Are yet Another Potential Pitfall in the Interpretation of Positive Urovysion Fluorescence In-Situ Hybridization (UV FISH) Results
N Motiwala, SC Drury, P Ramalingam, MK Terris, SC Peiper, D Thiruvaiyaru, M Reid-Nicholson. Medical College of Georgia, Augusta, GA; Charlie Norwood Veterans Affairs Hospital, Augusta, GA; Augusta State University, Augusta, GA
Background: UV FISH is an FDA approved test for the diagnosis and surveillance of urothelial carcinomas (UC). Renal tumor (RT) cells may also be shed in urine and we encountered such a case with positive UV FISH. We sought to determine if RTs express chr. abnormalities similar to those seen in UC and if so could cause a false positive FISH result in urine cytology.
Design: UV FISH probes were applied to paraffin blocks from 14 low-grade (LG, Furhman 1&2) and 12 high-grade (HG, Furhman 3&4) clear cell renal cell carcinoma (CCC), 8 papillary, (PRCC) (type 1&2), 3 sarcomatoid (SRCC), 2 chromophobe (CRCC), and 5 oncocytomas. Tumors were evaluated for polysomy 3, 7 and 17 and loss of both 9p21 alleles in > or =10% of cells.
Results: The results of hybridization are shown in tables 1 and 2.
Distribution of UV FISH Results
|Diagnosis||Positive FISH||Negative FISH||Failed FISH||Total (%)|
|LG CCC||3 (21%)||11 (79%)||0||14 (32%)|
|HG CCC||6 (50%)||5 (42%)||1 (8%)||12 (27%)|
|PRCC 1||2 (40%)||3 (60%)||0||5 (11.3%)|
|PRCC 2||0||3 (100%)||0||3 (7%)|
|CRCC||1 (50%)||0||1 (50%)||2(4.4%)|
|SRCC||2 (67%)||1 (33%)||0||3 (7%)|
|Oncocytoma||2 (40%)||3 (60%)||0||5 (11.3%)|
|Total||16 (36%)||26 (59%)||2 (5%)||44(100%)|
Polysomy Distribution by Tumor Type
|Diagnosis||Polysomy 3||Polysomy 7||Polysomy 17||Polysomy 9p21|
Logistic regression analysis revealed that poly chr. 17 had a statistically significantly association with PRCC but not with the other renal tumors (p-value 0.0027). No other chr. abnormality including poly chr. 17 had a statistically significant association with grade/ stage of malignant tumors.
Conclusions: We found that the chr. abnormalities tested for by UV FISH are also seen in benign and malignant RTs. Poly chr. 17 has a statistically significant association with PRCC but not other tumor types. UV FISH is therefore not specific for UC and false positive results may occur in the urine of patients with RTs. It is therefore prudent to correlate UV FISH results with clinical and radiologic findings both at initial diagnosis and follow up.
Category: Genitourinary (including renal tumors)
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 151, Tuesday Afternoon