title: Expression of c-kit (CD117) in Spitz nevus and malignant melanoma.
abstract: BACKGROUND
  CD117, the receptor for kit-ligand, which is a growth factor for melanocyte migration and proliferation, has shown differential staining in various benign and malignant melanocytic lesions. The purpose of this study is to compare CD117 immunohistological staining in Spitz nevus versus malignant melanoma, to determine whether CD117 can aid in the diagnosis of these two lesions.
  
  
  METHODS
  CD-117 immunohistological staining was performed in 22 clinically and pathologically diagnosed pigmented lesions including 9 cases of Spitz nevus, 10 cases of primary MM and 3 cases of metastatic melanoma.
  
  
  RESULTS
  There was no significant difference in CD117 staining in either epidermis or dermis between Spitz nevi and primary melanomas. However staining of metastatic melanomas is less than dermal staining of primary MM and Spitz nevus.
  
  
  CONCLUSIONS
  CD117 is unlikely a useful diagnostic tool in differentiating Spitz nevus from primary MM. On the other hand, CD 117 may be useful in differentiating metastatic melanoma from primary melanoma in patients who had a history of melanoma and who present with new dermal lesions.
authors.affiliation: Department of Dermatology, University of Colorado Health Science Center, Aurora, CO 80045-0510, USA. isabel.zhu@uchsc.edu
authors.forename: Y
authors.initials: Y
authors.lastname: Isabel Zhu
authors.forename: James E
authors.initials: JE
authors.lastname: Fitzpatrick
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008544:Melanocytes / Q000378:metabolism / Q000473:pathology; D008545:Melanoma / Q000378:metabolism* / Q000556:secondary; D018332:Nevus, Epithelioid and Spindle Cell / Q000378:metabolism* / Q000473:pathology; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D019009:Proto-Oncogene Proteins c-kit