SOX10 – Antibody Lexicon

by Jan Klos

Background

The SOX family of transcription factors (encoded by on chromosome 22q13.1) is involved in the regulation of embryonic development and the determination of cell fate. SOX10 is a transport protein between nucleus and a cytoplasm and acting as a transcriptional activator. It is important for development of neural crest and peripheral nervous system especially Schwann cells and melanocytes. SOX10 is also involved in the generation of myelin. There is evidence that SOX10 gene expression may be regulated by Microphtalmia Transcription Factor (MITF). Mutations in SOX10 are associated with Waardenburg syndrome and uveal melanoma. Some mutations may contribute to Hischprung`s disease. Despite a wide overlap in expression with S100 protein, there are important differences in reactivity with different tissues (eg. S100 stains positive chondroid tumors, chordoma, varying percentage of lipomatous tumors and a subset of adenocarcinomas where SOX10 is usually negative), which can be used in differential diagnosis of tumors.

Expression in normal cells

Nuclei of glial cells, Schwann cells, melanocytes and myoepithelial cells.

Expression in tumors

Many different tumors showing differentiation in above directions are positive, however percentage of positive cases is varying. Virtually all cases of melanocytic nevi and malignant melanoma (including desmoplastic and spindle cell melanomas, however the reactivity may be focal), schwannoma, neurofibroma, granular cell tumor, clear cell sarcoma of tendons and aponeuroses are positive. Majority of cases of salivary gland tumors (acinic cell carcinoma, adenoid cystic carcinoma, myoepithelioma, epithelial-myoepithelial and myoepithelial carcinoma, pleomorphic adenoma, canalicular adenoma) as well as oligodendroglioma, astrocytoma and glioblastoma are reported positive. About half of cases of basal-like and metaplastic triple-negative breast carcinomas but only rare cases of luminal type breast ductal carcinoma are positive. Minority of malignant nerve sheath tumor, some cases of adenocarcinoma of salivary glands and synovial sarcoma show positive staining. Negative are all other epithelial and mesenchymal tumors. Tumors like neuroblastoma, paraganglioma/pheochromocytoma and epithelial neuroendocrine tumors show positive staining only in sustentacular cells.

Staining pattern

Nuclear.

Control tissue

Skin and appendix.

Application

Detection of melanocytic, schwannian and myoepithelial neoplasms where SOX10 is more specific and probably more sensitive than S100 protein
Detection of metastatic melanoma in lymph nodes
Differential diagnosis of triple negative breast carcinoma in metastatic setting

by Jan Klos

Background

Expression in normal cells

Expression in tumors

Staining pattern

Control tissue

Application

Selected references