Wasco MJ et al. – Both PAX-2 and -H2AX are sensitive markers for diagnosis of metastatic renal cell carcinoma (RCC), with improved ease of interpretation compared with RCC-Ma; combination of all 3 markers identified 87% of cases; failure to stain for both PAX-2 and -H2AX suggests against, but does not disprove, RCC diagnosis Methods
Study of use of two new immunostains, PAX-2 and -H2AX, in FNA material for diagnosis of metastatic RCC and in comparison with RCC-Ma
Identification of 29 cases of metastatic RCC and TMA of an additional 30 RCC cases
Results
RCC-Ma in a membranous pattern of staining identified 15/27 (56%) metastatic RCC; interpretation complicated by focality of staining and non-specific cytoplasmic staining
PAX-2 stained 23/29 (79%) of tumors in a nuclear stain, most strongly
Gamma-H2AX stained 19/26 (73%) of metastatic RCC strongly in a nuclear stain
In the TMA, strong, diffuse nuclear staining with -H2AX present in 22/30 RCC (73%)
With weak staining included as positive, 26/30 (87%) were positive
PAX-2 stained RCC TMA with a lower percentage at 56%, including weaker staining intensity
Both PAX-2 and -H2AX showed patchy staining of normal renal tubules
