SOX-10 and MiTF expression in cellular and 'mixed' neurothekeoma.
BACKGROUND
Neurothekeoma and nerve sheath myxoma have long been interpreted as related tumors that share nerve sheath linage. Lack of S100 expression in neurothekeoma and similarities of gene expression profiles between neurothekeoma and fibrohistiocytic tumors have created reasonable doubt about this concept. SOX-10 represents a marker for schwannian and melanocytic differentiation, and is expressed in other tumors of nerve sheath linage. Microphthalmia transcription factor (MiTF) expression has been repeatedly reported in cellular neurothekeoma in the recent literature and was proposed as a helpful marker in this entity.


METHODS
We investigated 25 cases of cellular neurothekeoma, 8 cases of mixed neurothekeoma and 1 case of nerve sheath myxoma for the expression of SOX-10, MiTF, S100, NKI/C3, Melan-A and smooth muscle actin (SMA) using immunohistochemistry.


RESULTS
A lack of SOX-10 expression was demonstrated in 100% of cellular and mixed neurothekeomas, but was present in the case of nerve sheath myxoma. More than two thirds of neurothekeomas showed very focal or no reactivity with MiTF.


CONCLUSIONS
Our data suggest that neurothekeoma and nerve sheath myxoma are unrelated, and that cellular and mixed neurothekeoma may not be of nerve sheath lineage. In addition, MiTF should not be regarded as a useful marker in neurothekeoma.
Research Unit Dermatopathology, Department of Dermatology and Venerology, Medical University of Graz, Graz, Austria.
Isabella
I
Fried
Panitta
P
Sitthinamsuwan
Sorranart
S
Muangsomboon
Steven
S
Kaddu
Lorenzo
L
Cerroni
Timothy H
TH
McCalmont
D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051739:Microphthalmia-Associated Transcription Factor / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged; D018321:Neurothekeoma / Q000145:classification* / Q000378:metabolism / Q000473:pathology*; D055757:SOXE Transcription Factors / Q000032:analysis / Q000096:biosynthesis*; D055815:Young Adult
D014408:Biomarkers, Tumor; C497234:MITF protein, human; D051739:Microphthalmia-Associated Transcription Factor; C527923:SOX10 protein, human; D055757:SOXE Transcription Factors
MiTF; SOX-10; nerve sheath myxoma; neurothekeoma