The utility of Pax-2 as an immunohistochemical marker for renal cell carcinoma in cytopathology.
Pax-2 is a homeogene expressed during kidney development. Its expression in renal cell carcinoma (RCC) has been previously evaluated in histologic samples with a high sensitivity and specificity. Here, we investigated the utility of Pax-2 immunohistochemistry (IHC) for RCC in cytologic material, in comparison with a variety of other neoplasms. Pax-2 IHC was performed on cell block sections of 33 RCCs (14 primary, 19 metastatic) and 35 non-RCC malignancies, including 26 carcinomas, five mesenchymal tumors, one neuroblastoma, two melanomas, and one lymphoma, from fine-needle aspirations and body fluids. The presence or absence of nuclear staining and its intensity and distribution in positive cases were evaluated. Of 33 RCCs, Pax-2 was positive in 20 (61%) and negative in 13 (39%). All staining was nuclear, with an admixture of weakly or strongly staining nuclei. Only an endometrial adenocarcinoma was positive in the non-RCC group. The sensitivity and specificity of Pax-2 IHC for RCC were 61 and 97%, respectively. Pax-2 is a moderately sensitive and highly specific marker for RCC in cytologic material, with a lower sensitivity compared with tissue sections, likely due to a patchy expression pattern, and should be included in the immunohistochemical work-up of malignancies.
Gokden
Neriman
N
Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
Kemp
Susan A
SA
Gokden
Murat
M
D014408:Biomarkers, Tumor / Q000032:analysis*; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000175:diagnosis* / Q000556:secondary; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000737:chemistry / Q000175:diagnosis*; D051762:PAX2 Transcription Factor / Q000032:analysis*; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D051762:PAX2 Transcription Factor