The role of SOX-10 in identifying nodal metastasis in canine malignant melanoma.

Diagnosing early nodal metastases in canine malignant melanoma is challenging due to the morphological similarities between nodal melanophages and neoplastic melanocytes, and the limitations of conventional immunohistochemical markers like melan-A, which only labels a subset of tumor cells and requires tissue bleaching. This retrospective study investigated the utility of the immunohistochemical marker SOX-10, a nuclear transcription factor, in identifying metastatic cells in lymph nodes (LNs) from dogs with oral, labial, or digital malignant melanoma undergoing regional or sentinel lymphadenectomy. The analysis included 49 LNs from 27 dogs with oral (n = 10), labial (n = 9), and digital (n = 8) melanoma.