title: Expression of Sox-9 in metastatic melanoma--a potential diagnostic pitfall.
abstract: SOX-9 was originally identified as a master regulator gene that plays a role in the differentiation of mesenchymal cells to chondrocytes. Since then, SOX-9 has been implicated in neural crest development and has emerged as a transcriptional regulator of melanogenesis. Because the role of immunohistochemical detection of SOX-9 in the routine diagnosis of melanoma has not been previously described, we attempted to elucidate the spectrum and labeling characteristics of this antibody in a large cohort of patients with metastatic melanoma. We analyzed the expression of SOX-9 on sections of metastatic melanoma in a tissue microarray and compared the expression of this marker with 3 commonly used melanocytic markers (MART-1, HMB-45 antigen, and S-100 protein). SOX-9 expression was noted in 52 of the 62 cases (83.9%). In comparison, HMB-45 was positive in 53 of the 62 cases (85.5%), MART-1 was positive in 59 of the 62 cases (95.1%), and S-100 protein was positive in 57 of the 62 cases (95%). Interestingly, there were 5 tumors that were negative for 2 or more markers while being positive for SOX-9. Furthermore, 3 of these were negative for all markers except for SOX-9. Our study illustrates that SOX-9 is expressed in a high percentage of melanomas. Furthermore, SOX-9 may be a useful adjunct in the work-up of metastatic melanoma, in such cases where the tumor is negative for the other commonly used melanocytic markers. Last, our data confirm that SOX-9 is not a specific marker for tumors of cartilage lineage and may be expressed in other tumors of neural crest origin.
authors.affiliation: From the Department of Pathology, MD Anderson Cancer Center, Houston, TX.
authors.forename: Priya
authors.initials: P
authors.lastname: Rao
authors.forename: Gregory N
authors.initials: GN
authors.lastname: Fuller
authors.forename: Victor G
authors.initials: VG
authors.lastname: Prieto
mesh_terms: D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D003951:Diagnostic Errors / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D058965:MART-1 Antigen; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D058950:Melanoma-Specific Antigens; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D012189:Retrospective Studies; D009418:S100 Proteins / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000378:metabolism*; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D046888:Tissue Array Analysis; D055815:Young Adult
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058965:MART-1 Antigen; C548667:MLANA protein, human; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D009418:S100 Proteins; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human