title: Cyclooxygenase-2 expression in dermatofibroma and dermatofibrosarcoma protuberans.
abstract: BACKGROUND
  Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) occasionally resemble each other histologically but differ in histogenesis and biological behavior. This study sought to determine if these lesions can be differentiated by the quantity or quality of expression of cyclooxygenase-2 (COX-2), an enzyme associated with both reactive and neoplastic processes.
  
  
  METHODS
  Formalin-fixed and paraffin-embedded samples from 20 DFs and 20 DFSPs were stained immunohistochemically with antibodies directed against COX-2. Staining was evaluated semiquantitatively for percentage and intensity using a three-tiered system. DFs were graded and analyzed by cellularity. Findings within the tumors were compared with fibrocyte staining in adjacent tissue. The results were analyzed.
  
  
  RESULTS
  Nineteen DFs (95%) and 15 DFSPs (75%) were immunopositive for COX-2; this difference was not statistically significant. Highly cellular DFs showed more widespread (p = 0.0039; r = 0.614) and more intense (p = 0.0586; r = 0.429) staining than less cellular DFs and more prominent staining in adjacent fibroblasts (p = 0.044; r = 0.608).
  
  
  CONCLUSIONS
  COX-2 immunostaining does not distinguish DFs from DFSPs. However, the enzyme is expressed more widely and more intensely in more cellular, possibly younger, DFs. The prominent expression of COX-2 in DFSP may have clinical implications for treatment with COX-2 inhibitors in tumors that are not amenable to surgery.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Rabin Medical Center, Beilinson Campus, Petah Tiqwa, Israel.
authors.forename: Neta
authors.initials: N
authors.lastname: Adler
authors.forename: Cochava
authors.initials: C
authors.lastname: Tsabari
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Sulkes
authors.forename: Dean
authors.initials: D
authors.lastname: Ad-El
authors.forename: Meora
authors.initials: M
authors.lastname: Feinmesser
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000032:analysis / Q000378:metabolism*; D018223:Dermatofibrosarcoma / Q000175:diagnosis / Q000201:enzymology*; D003937:Diagnosis, Differential; D019084:Fluorescent Antibody Technique, Indirect; D018219:Histiocytoma, Benign Fibrous / Q000175:diagnosis / Q000201:enzymology*; D006801:Humans; D012878:Skin Neoplasms / Q000175:diagnosis / Q000201:enzymology*
chemical_list: D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2