title: LN2, CD10, and Ezrin Do Not Distinguish Between Atypical Fibroxanthoma and Undifferentiated Pleomorphic Sarcoma or Predict Clinical Outcome.
abstract: BACKGROUND
  Atypical fibroxanthoma (AFX) is a rare cutaneous spindled cell neoplasm. For both diagnostic and therapeutic purposes, it is important to distinguish AFX from other poorly differentiated tumors, including undifferentiated pleomorphic sarcoma (UPS).
  
  
  OBJECTIVE
  The authors aimed to identify the clinical, histologic, and immunohistochemical expression of LN2, ezrin, and CD10 in AFX and UPS tumors.
  
  
  METHODS
  The authors retrospectively examined the charts of patients with AFX and UPS treated with Mohs micrographic surgery (MMS) at 2 academic institutions. Patient demographics, tumor characteristics, and clinical course data were collected. Immunohistochemical stains were performed on primary and recurrent AFX and UPS tumors with monoclonal antibodies against the B-cell marker LN2 (CD74), CD10, and ezrin.
  
  
  RESULTS
  In the series of 169 patients with AFX included in this study, local recurrence was rare at 3%. In contrast, the seven patients with UPS had an aggressive clinical course with 1 local recurrence and 2 distant metastases. Immunohistochemistry staining for ezrin, LN2, and CD10 were similar in AFX and UPS tumors.
  
  
  CONCLUSIONS
  AFX can be treated with MMS with rare instances of recurrence. Undifferentiated pleomorphic sarcoma has a more aggressive clinical course with increased risk for recurrence and metastasis. Staining with ezrin, LN2, and CD10 did not differentiate AFX or UPS tumors.
authors.affiliation: *Division of Dermatology, Department of Medicine, Vanderbilt University, Nashville, Tennessee; †Department of Dermatology, University of Oklahoma, Oklahoma City, Oklahoma; ‡Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Allison
authors.initials: A
authors.lastname: Hanlon
authors.forename: Thomas
authors.initials: T
authors.lastname: Stasko
authors.forename: Dan
authors.initials: D
authors.lastname: Christiansen
authors.forename: Nika
authors.initials: N
authors.lastname: Cyrus
authors.forename: Anjela
authors.initials: A
authors.lastname: Galan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D003598:Cytoskeletal Proteins / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D051677:Histiocytoma, Malignant Fibrous / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality / Q000601:surgery; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D015580:Mohs Surgery; D015260:Neprilysin / Q000032:analysis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012509:Sarcoma / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality / Q000601:surgery; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality / Q000601:surgery; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States; D000099149:Ezrin
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D014408:Biomarkers, Tumor; D003598:Cytoskeletal Proteins; D000949:Histocompatibility Antigens Class II; D015260:Neprilysin; D000099149:Ezrin; C045084:invariant chain