title: Expression of renal cell carcinoma-associated markers erythropoietin, CD10, and renal cell carcinoma marker in diffuse malignant mesothelioma and metastatic renal cell carcinoma.
abstract: BACKGROUND
  Metastatic renal cell carcinoma (MRCC) involving the thorax can be difficult to distinguish from diffuse malignant mesothelioma (DMM) using traditional morphologic approaches. Standard panels of immunohistochemical markers are of limited benefit.
  
  
  OBJECTIVE
  To investigate several antibodies to renal cell carcinoma-associated proteins for differentiating MRCC from DMM.
  
  
  METHODS
  One hundred DMMs and 20 MRCCs were evaluated for immunoexpression of erythropoietin. The same cases and an additional 45 DMMs were evaluated for CD10 and renal cell carcinoma marker (RCCMa) immunoreactivity.
  
  
  RESULTS
  Erythropoietin was expressed in 100% of DMMs and MRCCs. Staining for CD10 was observed in 54% of DMMs and 100% of MRCCs. RCCMa stained 26% of DMMs and 55% of MRCCs. Although erythropoietin staining was similarly strong and diffuse in both DMM and MRC, patterns of staining for RCCMa and CD10 differed between MRCC and DMM. Immunoreactivity was strong and diffuse for both RCCMa and CD10 in most MRCCs. Of CD10-positive DMMs, nearly half showed staining in less than 50% of tumor cells and about one fourth of positive cases exhibited only weak to moderately intense staining. Only half of RCCMa-positive DMMs showed staining in more than 49% of tumor cells and staining was only weak to moderately intense in most cases.
  
  
  CONCLUSIONS
  Given the overlap in the expression of renal cell carcinoma markers in MRCC and DMM, results with these markers must be interpreted cautiously and should be used in conjunction with mesothelium-associated markers. Differences in expression may potentially help distinguish MRCC from DMM inasmuch as strong and diffuse expression of RCCMa and CD10 supports a diagnosis of MRCC over DMM.
authors.affiliation: Department of Pathology, University of Vermont/Fletcher Allen Health Care, Burlington, VT 05401, USA. kelly.butnor@vtmednet.org
authors.forename: Kelly J
authors.initials: KJ
authors.lastname: Butnor
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Nicholson
authors.forename: D Craig
authors.initials: DC
authors.lastname: Allred
authors.forename: Dani S
authors.initials: DS
authors.lastname: Zander
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Henderson
authors.forename: Roberto
authors.initials: R
authors.lastname: Barrios
authors.forename: Abida K
authors.initials: AK
authors.lastname: Haque
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Allen
authors.forename: Deanna E
authors.initials: DE
authors.lastname: Killen
authors.forename: Philip T
authors.initials: PT
authors.lastname: Cagle
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000556:secondary; D003937:Diagnosis, Differential; D004921:Erythropoietin / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D008654:Mesothelioma / Q000378:metabolism* / Q000473:pathology; D015260:Neprilysin / Q000378:metabolism*; D010997:Pleural Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D004921:Erythropoietin; D015260:Neprilysin