Case Number : Case 1538 - 17 May Posted By: Guest

Melanoma, probably metastatic. I expect s100 and mart1 to be positive here too

Melanoma.

Agree. Metastatic "in transit" melanoma ( also intravascular maybe ).

Metastatic breast carcinoma

Small numbers of breast carcinomas about (10-12%) are positive for SOX10. other melanocytic markers such as S100 and melan A as well as mammaglobin or GCDFP15 worth a try.

Metastatic breast carcinoma

If Melan A is negative the differential could also include a metastatic breast carcinoma with a basal-like phenotype as you perfectly suggested http://www.ncbi.nlm.nih.gov/pubmed/23260325

Metastatic melanoma certainly likely. However important to remeber that SOX10 does stain other tumours including neural and myoepitheiomas. On high power, the cells have eccentric nuclei and plasmacytoid appearance. Whilst this morphology would do for a melanoma too, important to do a panel of markers to exclude myoepithelioma.

Yes, and a metastatic breast Ca too. ..thanks for the ref Raul!

I would favour a metastasis from a breast carcinoma (ductal/pleomorphic lobular). The infiltrate has a very interstitial pattern of growth, and I think this would be unusual for a melanoma (in-transit/primary dermal). Would have expected a more nodular growth pattern with a melanoma. Requires a complete IHC panel. Thanks for the article Raul.

Yes. Morphologically this tumor looks like a pleomorphic solid lobular mammary cancer, but also like a melanoma...So extraimmunos ( or clinic history) should to resolve the diagnostic puzzle...Thanks to all of you for information about SOX 10 and special types of breast cancer..

Great job. Point here is a panel of immunohistochemical studies is important to determine lineage and sox10 staining in breast and salivary gland tumors is well worth noting. The lesional cells are positive for Melan A and S100, and negative for keratin markers. Diagnosis: metastatic melanoma. Patient has history of Stage IV melanoma.