title: Pericyte Antigens in Perivascular Soft Tissue Tumors.
abstract: BACKGROUND
  Perivascular soft tissue tumors are relatively uncommon neoplasms of unclear line of differentiation, although most are presumed to originate from pericytes or modified perivascular cells. Among these, glomus tumor, myopericytoma, and angioleiomyoma share a spectrum of histologic findings and a perivascular growth pattern. In contrast, solitary fibrous tumor (previously termed hemangiopericytoma) was once hypothesized to have pericytic differentiation.
  
  
  METHODS
  Here, we systematically examine pericyte immunohistochemical markers among glomus tumor (including malignant glomus tumor), myopericytoma, angioleiomyoma, and solitary fibrous tumor. Immunohistochemical staining and semiquantification was performed using well-defined pericyte antigens, including αSMA, CD146, and PDGFRβ.
  
  
  RESULTS
  Glomus tumor and myopericytoma demonstrate diffuse staining for all pericyte markers, including immunohistochemical reactivity for αSMA, CD146, and PDGFRβ. Malignant glomus tumors all showed some degree of pericyte marker immunoreactivity, although it was significantly reduced. Angioleiomyoma shared a similar αSMA + CD146 + PDGFRβ+ immunophenotype; however, this was predominantly seen in the areas of perivascular tumor growth. Solitary fibrous tumors showed patchy PDGFRβ immunoreactivity only.
  
  
  CONCLUSIONS
  In summary, pericyte marker expression is a ubiquitous finding in glomus tumor, myopericytoma, and angioleiomyoma. Malignant glomus tumor shows a comparative reduction in pericyte marker expression, which may represent partial loss of pericytic differentiation. Pericyte markers are essentially not seen in solitary fibrous tumor. The combination of αSMA, CD146, and PDGFRβ immunohistochemical stainings may be of utility for the evaluation of pericytic differentiation in soft tissue tumors.
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: Shen
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Swati
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Yu-Hsin
authors.initials: YH
authors.lastname: Yen
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Greg
authors.initials: G
authors.lastname: Asatrian
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Marco
authors.initials: M
authors.lastname: Mravic
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Chia
authors.initials: C
authors.lastname: Soo
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Kang
authors.initials: K
authors.lastname: Ting
authors.affiliation: University of California, Los Angeles, CA, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Dry
authors.affiliation: University of California, Los Angeles, CA, USA University of Edinburgh, Edinburgh, UK.
authors.forename: Bruno
authors.initials: B
authors.lastname: Peault
authors.affiliation: University of California, Los Angeles, CA, USA Awjames@mednet.ucla.edu.
authors.forename: Aaron W
authors.initials: AW
authors.lastname: James
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D020286:Pericytes / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies; D012983:Soft Tissue Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor
keywords: CD146; Mel-CAM; PDGFRB; angioleiomyoma; glomus tumor; hemangiopericytoma; myopericytoma; pericyte; platelet-derived growth factor receptor; solitary fibrous tumor