title: The vascular marker CD31 also highlights histiocytes and histiocyte-like cells within cutaneous tumors.
abstract: OBJECTIVE
  While useful in diagnosing angiosarcomas, CD31 can also highlight histiocytes within soft tissue tumors and lead to errors in diagnosis. We sought to determine how often CD31 highlights cutaneous histiocytomas and histiocytoma mimics.
  
  
  METHODS
  We examined eight epithelioid cell histiocytomas (ECHs), 12 xanthogranulomas (XGs), nine cases of Langerhans cell histiocytosis (LCH), eight reticulohistiocytomas, 11 xanthomas, 29 atypical fibroxanthomas, nine granular cell tumors, four cases of angiolymphoid hyperplasia with eosinophilia, nine intradermal Spitz nevi, and nine angiosarcomas with antibodies directed against CD31, CD34, CD163, and factor VIII.
  
  
  RESULTS
  CD31 marked cells in three of 12 XGs, four of nine cases of LCH, one of eight reticulohistiocytomas, one of 11 xanthomas, 10 of 29 atypical fibroxanthomas, four of four cases of angiolymphoid hyperplasia with eosinophilia, nine of nine angiosarcomas, zero of nine granular cell tumors, and zero of eight ECHs. CD34 and factor VIII were negative in all nonvascular cases.
  
  
  CONCLUSIONS
  Our results indicate that CD31 can mark lesional cells and imitate vascular tumors in cutaneous histiocytomas and histiocytoma mimics, an error that can be avoided by using a panel of antibodies.
authors.affiliation: From the Departments of Pathology, Stanford University Medical Center, Stanford, CA.
authors.forename: Vijay
authors.initials: V
authors.lastname: Vanchinathan
authors.forename: Neda
authors.initials: N
authors.lastname: Mirzamani
authors.affiliation: From the Departments of Pathology, Stanford University Medical Center, Stanford, CA.
authors.forename: Neda
authors.initials: N
authors.lastname: Mizramani
authors.affiliation: From the Departments of Pathology, Stanford University Medical Center, Stanford, CA.
authors.forename: Ramya
authors.initials: R
authors.lastname: Kantipudi
authors.affiliation: From the Departments of Pathology, Stanford University Medical Center, Stanford, CA.
authors.forename: Erich J
authors.initials: EJ
authors.lastname: Schwartz
authors.affiliation: From the Departments of Pathology, Stanford University Medical Center, Stanford, CA. From the Departments of Dermatology, Stanford University Medical Center, Stanford, CA. sundram@stanford.edu.
authors.forename: Uma N
authors.initials: UN
authors.lastname: Sundram
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006394:Hemangiosarcoma / Q000737:chemistry / Q000175:diagnosis*; D006644:Histiocytes / Q000378:metabolism*; D018219:Histiocytoma, Benign Fibrous / Q000737:chemistry / Q000175:diagnosis*; D051677:Histiocytoma, Malignant Fibrous / Q000737:chemistry / Q000175:diagnosis*; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D019408:Platelet Endothelial Cell Adhesion Molecule-1
keywords: CD31; Cutaneous tumors; Histiocytes; Vascular tumors