title: Comparison of PAX-2, RCC antigen, and antiphosphorylated H2AX antibody (gamma-H2AX) in diagnosing metastatic renal cell carcinoma by fine-needle aspiration.
abstract: 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 gamma-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 gamma-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 gamma-H2AX demonstrated patchy staining of normal renal tubules, PAX-2 to a greater extent. Both PAX-2 and gamma-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 gamma-H2AX suggests against, but does not disprove, a diagnosis of RCC.
authors.affiliation: The University of Michigan Medical School, Department of Pathology, Ann Arbor, Michigan 48109-0602, USA. mwasco@med.umich.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Wasco
authors.forename: Robert T
authors.initials: RT
authors.lastname: Pu
mesh_terms: D000912:Antibodies, Neoplasm; D045163:Antibodies, Phospho-Specific; D000951:Antigens, Neoplasm / Q000276:immunology*; D044963:Biopsy, Fine-Needle; D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D006657:Histones / Q000276:immunology*; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D009362:Neoplasm Metastasis; D051762:PAX2 Transcription Factor / Q000276:immunology*; D010766:Phosphorylation
chemical_list: D000912:Antibodies, Neoplasm; D045163:Antibodies, Phospho-Specific; D000951:Antigens, Neoplasm; C468783:H2AX protein, human; D006657:Histones; D051762:PAX2 Transcription Factor; C497318:PAX2 protein, human