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Published on: February 8, 2019
S100A6 expression in fibrohistiocytic lesions
D R Fullen1, J A Reed, B Finnerty
1Department of Pathology, University of Michigan Hospitals, Ann Arbor, Michigan, USA. dfullen@umich.edu
Journal of Cutaneous Pathology
|June 13, 2001
Summary
S100A6 protein is present in some fibrohistiocytic lesions, expanding their known immunophenotypes. While helpful for atypical fibroxanthomas (AFX), S100A6 offers limited added benefit over factor XIIIa for diagnosing other fibrohistiocytic conditions.
Area of Science:
- Dermatopathology
- Immunohistochemistry
- Oncology
Background:
- S100A6 protein is found in various lesions like melanoma and tumors.
- Dermal dendrocytes (DD) in skin also express S100A6.
- This study investigates S100A6 expression in fibrohistiocytic lesions.
Purpose of the Study:
- To evaluate S100A6 protein expression in a range of cutaneous fibrohistiocytic lesions.
- To determine if S100A6 positivity can be added to the immunophenotype of these lesions.
- To assess the utility of S100A6 in the differential diagnosis of fibrohistiocytic conditions.
Main Methods:
- Immunohistochemical analysis of formalin-fixed, paraffin-embedded tissues.
- Antibodies used: S100A6, S100B, factor XIIIa, and MAC387.
- Tested lesions included fibrous papules, dermatofibromas, and atypical fibroxanthomas.
Main Results:
- S100A6 positivity was observed in dermal dendrocytes of fibrous papules, dermatofibromas, and fibromas.
- No S100A6 staining was detected in dermatofibrosarcoma protuberans (DFSP).
- S100A6 demonstrated superior staining compared to factor XIIIa in atypical fibroxanthomas (AFX).
Conclusions:
- The immunophenotype of certain fibrohistiocytic lesions can be expanded to include S100A6.
- S100A6 shows potential utility in diagnosing AFX.
- For most fibrohistiocytic lesions, S100A6 offers limited diagnostic advantage over factor XIIIa.
