title: PAX2 and PAX8: useful markers for metastatic effusions.
abstract: OBJECTIVE
  It was the aim of this study to determine the utility of PAX2 and PAX8 in cytology effusions with metastatic tumor.
  
  
  METHODS
  PAX2 and PAX8 immunohistochemical staining was performed on cell blocks of 89 pleural, pericardial and peritoneal effusions with benign diagnoses (18 cases), or secondary to renal cell carcinoma (RCC; 9 cases), müllerian carcinoma (21 cases) or non-müllerian carcinoma (41 cases).
  
  
  RESULTS
  PAX2 stained 0% (0/18) of controls, 100% (8/8) of RCCs, 35% (7/20) of müllerian carcinomas, and 2% (1/41) of non-müllerian carcinomas. PAX8 stained 6% (1/18) of control cases, 100% (9/9) of RCC cases, 100% (20/20) of müllerian carcinomas, and 5% (2/41) of non-müllerian carcinomas. PAX2 was 35% sensitive and 95% specific for müllerian carcinoma and 100% sensitive and 95% specific for RCC. PAX8 was 100% sensitive and 95% specific for müllerian carcinoma and 100% sensitive and 95% specific for RCC.
  
  
  CONCLUSIONS
  PAX8 is more sensitive than PAX2 for metastatic effusions from müllerian carcinomas (100 vs. 35%), while also having a higher intensity of staining than PAX2. However, PAX2 and PAX8 are both highly sensitive and specific for RCCs. PAX2 and PAX8 are valuable diagnostic markers for metastatic müllerian carcinomas and RCCs in effusion cytology. PAX8 is superior for carcinomas of müllerian origin.
authors: Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Tex., USA.
authors: Lindsay
authors: L
authors: Waters
authors: Suzanne
authors: S
authors: Crumley
authors: Luan
authors: L
authors: Truong
authors: Dina
authors: D
authors: Mody
authors: Donna
authors: D
authors: Coffey
mesh_terms: D001202:Ascitic Fluid / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002277:Carcinoma / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D008297:Male; D009362:Neoplasm Metastasis; D051762:PAX2 Transcription Factor / Q000032:analysis / Q000096:biosynthesis*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000032:analysis / Q000096:biosynthesis*; D010490:Pericardial Effusion / Q000209:etiology / Q000378:metabolism*; D016066:Pleural Effusion, Malignant / Q000209:etiology / Q000378:metabolism*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D051762:PAX2 Transcription Factor; C497318:PAX2 protein, human; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors