Immunohistochemical staining of CD10 in atypical fibroxanthomas

J Cutan Pathol. 2007 May;34(5):415-9. doi: 10.1111/j.1600-0560.2006.00635.x.


Background: The histologic diagnosis of atypical fibroxanthoma (AFX) may be difficult at times with a differential diagnosis including spindle cell/desmoplastic melanoma and a poorly differentiated squamous cell carcinoma (SCC). While there are immunohistochemical stains that may be used to support a diagnosis of either melanoma or carcinoma, the diagnosis of AFX tends to be one of exclusion.

Methods: A total of 35 cases including 16 AFXs, 10 poorly differentiated SCCs and nine spindle cell/desmoplastic melanomas were stained with the antibody against CD10.

Results: There was strong (3+) diffuse expression of CD10 in 15/16 (94%) AFXs, weak (1+) to moderate (2+) patchy expression of CD10 in 5/10 (50%) SCCs and weak (1+) expression of CD10 in 3/9 (33%) spindle cell/desmoplastic melanomas.

Conclusion: CD10 expression is helpful in distinguishing between AFXs, carcinomas and melanomas and will be useful in a panel of antibodies when distinguishing between these entities.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis*
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology
  • Diagnosis, Differential
  • Female
  • Histiocytoma, Benign Fibrous / metabolism*
  • Histiocytoma, Benign Fibrous / pathology*
  • Humans
  • Immunohistochemistry
  • Male
  • Melanoma / metabolism
  • Melanoma / pathology
  • Middle Aged
  • Neprilysin / biosynthesis*
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology*


  • Biomarkers, Tumor
  • Neprilysin