SOX-10 (EP268)

Sry-related HMG-BOX gene 10 (SOX-10) is a nuclear transcription factor that participates in neural crest development and in the specification and differentiation of cells of melanocytic lineage.1 It has been recently shown to be a sensitive marker of melanoma, including conventional, spindled, and desmoplastic subtypes.2 SOX-10 was expressed by metastatic melanomas in sentinel lymph nodes, but not by other lymph node components such as dendritic cells which usually express S100 protein. Anti-SOX-10 has been shown to be superior to all other immunostains in detecting residual invasive and in situ melanoma.1-5 Anti-SOX-10 is also a useful marker in detecting both the in situ and invasive components of desmoplastic melanoma.6 It is known that the commonly used melanoma markers, anti-HMB-45 and anti-Melan-A, are poorly expressed in desmoplastic melanomas5 while it has been reported that anti-SOX-10 was moderately to strongly expressed in almost all desmoplastic melanomas.2 SOX-10 is diffusely expressed in schwannomas and neurofibromas. SOX-10 presence was not identified in any other mesenchymal and epithelial tumors except for myoepitheliomas and diffuse astrocytomas.2