title: Utility of immunohistochemical staining with FLI1, D2-40, CD31, and CD34 in the diagnosis of acquired immunodeficiency syndrome-related and non-acquired immunodeficiency syndrome-related Kaposi sarcoma.
abstract: BACKGROUND
  Kaposi sarcoma (KS) is a vascular tumor frequently associated with advanced human immunodeficiency virus infection, advanced age, or iatrogenic immunosuppression. Immunohistochemistry for CD31 and CD34, and more recently for FLI1 and D2-40, has been used as ancillary diagnostic tests for KS, despite little information regarding the sensitivities and differential staining patterns of the latter 2 markers in the major clinical subtypes and histologic stages of KS.
  
  
  OBJECTIVE
  This retrospective study aims to assess the prevalence of the vascular markers D2-40 and FLI1 in the main clinical subgroups and tumor stages of KS.
  
  
  METHODS
  Twenty-four cases of KS (12 acquired immunodeficiency syndrome [AIDS]-related cases and 12 non-AIDS-related cases; 11 nodular-stage and 13 patch/plaque-stage KS) were stained for CD34, CD31, D2-40, and FLI1 by immunohistochemistry. The distribution of immunoreactivity was compared between the clinical subtypes and tumor stages of KS using the Mann-Whitney test.
  
  
  RESULTS
  CD31, CD34, D2-40, and FLI1 strongly and diffusely stained tumor cells in 75%, 92%, 67%, and 92% of AIDS-related cases and 58%, 92%, 67%, and 75% of non-AIDS-related cases, respectively. Differences in the proportions of positive cases between AIDS-related and non-AIDS-related cases did not reach statistical significance. No significant staining differences were observed between nodular- and patch/plaque-stage KS either.
  
  
  CONCLUSIONS
  There are no differences in the distribution of immunohistochemical reactivity for CD31, CD34, D2-40, or FLI1 between AIDS-related and non-AIDS-related KS or between nodular- and patch/plaque-stage KS. All of the markers studied demonstrated high sensitivity in both clinical settings and both stages of tumor progression.
authors.affiliation: Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, USA. flavia.nunes@vanderbilt.edu
authors.forename: Flavia G Nunes
authors.initials: FG
authors.lastname: Rosado
authors.forename: Doha M
authors.initials: DM
authors.lastname: Itani
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Coffin
authors.forename: Justin M
authors.initials: JM
authors.lastname: Cates
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications; D058846:Antibodies, Monoclonal, Murine-Derived / Q000032:analysis*; D018952:Antigens, CD34 / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis; D003937:Diagnosis, Differential; D018450:Disease Progression; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D009367:Neoplasm Staging; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis*; D051789:Proto-Oncogene Protein c-fli-1 / Q000032:analysis*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012514:Sarcoma, Kaposi / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D018952:Antigens, CD34; D014408:Biomarkers, Tumor; C078433:FLI1 protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D051789:Proto-Oncogene Protein c-fli-1; C500987:monoclonal antibody D2-40