title: Identification of nodal metastases in melanoma using sox-10.
abstract: The presence of S100-positive dendritic cells hinders the identification of isolated melanoma tumor cells and micrometastases in sentinel lymph nodes. Sox-10, a transcription factor that plays an important role in schwannian and melanocytic cell development, is not expressed in dendritic cells. We investigated the diagnostic utility of Sox-10 in the identification of metastases in sentinel and nonsentinel lymph nodes for melanoma. We examined the expression pattern of Sox-10, as compared with S100, Melan-A, and HMB-45 in 93 lymph nodes (40 originally reported as positive and 53 originally reported as negative for metastasis) from 33 sentinel lymph node biopsies and regional lymphadenectomies. Sox-10 and S100 both highlighted metastases in 43 of 43 (100%) positive lymph nodes identified in this study; however, Sox-10 immunohistochemical staining significantly improved the detection of nodal metastases. The nuclear staining of Sox-10 promoted improved distinction between heavily pigmented melanophages and melanocytic metastases in 3 positive lymph nodes. In 2 lymph nodes, Sox-10 was critical in distinguishing S100-positive atypical nodal dendritic cells from tumor cells. Also, Sox-10 significantly improved the identification of micrometastases and isolated tumor cells as compared with S100 in 10 positive lymph nodes. Most importantly, Sox-10 identified micrometastases in 2 lymph nodes, originally reported as negative on S100, Melan-A, and HMB-45 immunostains. Therefore, Sox-10 is a comparable marker to S100 in identifying nodal metastases in melanoma and is especially useful in the setting of lymph nodes with heavily pigmented metastases, numerous S100-positive nodal dendritic cells, micrometastases, and isolated tumor cells.
authors.affiliation: Departments of Pathology, Stanford University Medical Center, Stanford, CA 94305, USA.
authors.forename: Charay
authors.initials: C
authors.lastname: Jennings
authors.forename: Jinah
authors.initials: J
authors.lastname: Kim
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies; D009418:S100 Proteins / Q000032:analysis / Q000378:metabolism; D055757:SOXE Transcription Factors / Q000032:analysis / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D009418:S100 Proteins; D055757:SOXE Transcription Factors