Premium
Comparison of PAX‐2, RCC antigen, and antiphosphorylated H2AX antibody (γ‐H2AX) in diagnosing metastatic renal cell carcinoma by fine‐needle aspiration
Author(s) -
Wasco Matthew J.,
Pu Robert T.
Publication year - 2008
Publication title -
diagnostic cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.417
H-Index - 65
eISSN - 1097-0339
pISSN - 8755-1039
DOI - 10.1002/dc.20839
Subject(s) - renal cell carcinoma , medicine , staining , stain , pathology , fine needle aspiration , immunostaining , metastatic carcinoma , clear cell , immunohistochemistry , carcinoma , biopsy
Diagnosing metastatic renal cell carcinoma (RCC) by fine‐needle aspiration (FNA) can be challenging. Existing antibodies supporting a diagnosis of RCC, including CD10 and RCC‐Ma, have problems with specificity and interpretation. In this report, we evaluate the use of two newer immunostains, PAX‐2 and γ‐H2AX, which to our knowledge have not been studied in FNA material, in the diagnosis of metastatic RCC and in comparison with RCC‐Ma. 29 cases of metastatic RCC were identified as well as a TMA of an additional 30 RCC cases. In the case cohort, RCC‐Ma in a membranous pattern of staining identified 15/27 (56%) metastatic RCC, although interpretation was made difficult in many cases due to 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 γ‐H2AX was present in 22/30 RCC (73%). If weak staining was also 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 γ‐H2AX demonstrated patchy staining of normal renal tubules, PAX‐2 to a greater extent. Both PAX‐2 and γ‐H2AX are sensitive markers for the diagnosis of metastatic RCC, with improved ease of interpretation when compared with RCC‐Ma. A combination of all 3 markers identified 87% of cases, and failure to stain for both PAX‐2 and γ‐H2AX suggests against, but does not disprove, a diagnosis of RCC. Diagn. Cytopathol. 2008; 36: 568–573. © 2008 Wiley‐Liss, Inc.