Diagnostic value of SOX-10 immunohistochemical staining for the detection of uveal melanoma

Abstract

ObjectivesSOX-10 has been shown to be a sensitive marker of cutaneous melanoma. This study aimed to evaluate Sox-10 expression in uveal melanoma.MethodsA total of 40 tissue blocks of enucleated eyes with uveal melanoma were cut and stained using an anti-SOX-10 mouse monoclonal antibody and HMB-45 antibody.ResultsSOX-10 showed exclusive nuclear positivity in 100% of the uveal melanoma cases (38/38). HMB-45 showed cytoplasmic positivity in 97.3 (37/38). Positivity for SOX-10 was also noted in the inner and outer nuclear layers of the retina in 78% of the enucleated eyes.ConclusionsSOX-10 expression proved to be the most sensitive marker for uveal melanoma, and therefore, we propose a modified panel for the diagnosis of uveal melanoma that includes both SOX-10 and HMB-45. The observation of distinct, diffuse nuclear SOX-10 expression in retinal inner and outer nuclear layers is a finding that warrants further investigation as a marker for retinoblastoma.

SOX‐10 staining in dermal scars

“…This IHC panel was chosen due to the specificity of SOX‐10 decreasing because of stain positivity in normal ocular structures . SOX‐10 has also shown exclusive nuclear positivity, as previously reported, in 100% of the uveal melanoma cases (38/38) . Danga et al described dual staining with Melan‐A and SOX‐10 that helped affirm the melanocytic lineage of Melan‐A positive dermal cells found in cutaneous excisions and re‐excisions of non‐melanocytic lesions .…”

“…In a study of uveal melanoma staining patterns of SOX‐10 and HMB45, Alghamdi et al proposed a modified IHC panel for the diagnosis of uveal melanoma, which includes both SOX‐10 and HMB‐45 . This IHC panel was chosen due to the specificity of SOX‐10 decreasing because of stain positivity in normal ocular structures . SOX‐10 has also shown exclusive nuclear positivity, as previously reported, in 100% of the uveal melanoma cases (38/38) .…”

“…It has been found to be negative in the most common dermal histologic mimics of DM, including scars, spindle squamous cell carcinoma, atypical fibroxanthoma, and dermal sarcomas . SOX‐10 is a reliable marker in evaluating sentinel lymph nodes for metastatic melanoma and identifying rare tumor cells in heavily regressed areas of metastatic melanoma with abundant melanophages . Immunohistochemical evaluation with SOX‐10 also has found utility in evaluation of intranodal spindle cell tumors …”

“…Dual cytoplasmic and nuclear staining may be prudent in the evaluation of re‐excision of melanoma with desmoplastic components, especially when the morphology of SOX‐10 staining cells are round and small. In a study of uveal melanoma staining patterns of SOX‐10 and HMB45, Alghamdi et al proposed a modified IHC panel for the diagnosis of uveal melanoma, which includes both SOX‐10 and HMB‐45 . This IHC panel was chosen due to the specificity of SOX‐10 decreasing because of stain positivity in normal ocular structures .…”

“…The SOX‐10 immunohistochemical (IHC) stain is largely used as a specific and sensitive marker for melanocytes and neural tissues . Melanocyte‐specific markers such as S100, HMB 45, and Melan A have been used to evaluate residual melanoma in the setting of desmoplastic melanoma (DM) and uveal melanoma . Recent studies have also showed that SOX‐10 is a sensitive and specific marker in the evaluation of DM .…”