Gokden Neriman, Kemp Susan A, Gokden Murat
Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
Diagn Cytopathol. 2008 Jul;36(7):473-7. doi: 10.1002/dc.20842.
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.
Pax-2是一种在肾脏发育过程中表达的同源基因。此前已在组织学样本中对其在肾细胞癌（RCC）中的表达进行了评估，具有较高的敏感性和特异性。在此，我们研究了Pax-2免疫组织化学（IHC）在细胞学材料中对RCC的应用价值，并与多种其他肿瘤进行了比较。对33例RCC（14例原发性，19例转移性）以及35例非RCC恶性肿瘤（包括26例癌、5例间叶组织肿瘤、1例神经母细胞瘤、2例黑色素瘤和1例淋巴瘤）的细针穿刺和体液的细胞块切片进行了Pax-2 IHC检测。评估了阳性病例中核染色的有无及其强度和分布情况。在33例RCC中，Pax-2阳性20例（61%），阴性13例（39%）。所有染色均为核染色，核染色有弱染或强染混合情况。非RCC组中只有1例子宫内膜腺癌呈阳性。Pax-2 IHC对RCC的敏感性和特异性分别为61%和97%。Pax-2是细胞学材料中RCC的一种中度敏感且高度特异的标志物，与组织切片相比敏感性较低，可能是由于其呈斑片状表达模式，应纳入恶性肿瘤的免疫组织化学检查中。
