Case Number : Case 2957 - 05 November 2021 Posted By: Dr. Richard Carr

Nodular Melanoma. 

Melanoma

BerEP4 negative and EMA is positive, p16 negative. p63 and p53 positive

Poorly differentiated carcinoma also do sox 10/HMB45 not miss a melanoma. p16 cannot be used for melanocytic lesion

Thanks for the stalwart responders. This case was c/o Dr Domenico Mesiano. S100 and MelanA were performed and negative. I regarded this lesion as a lymphoepithelioma-like carcinoma. I reviewed the literature on them a while back now but it appeared there was a metastatic rate in the region of ~25% of reported cases and I've seen a couple of cases metastasise myself. They may have an adnexal origin but as you're probably aware I think most cutaneous SCC are follicular "de novo" SCC. p16 here is highly aberrantly null and p53 is highly aberrantly weak / negative. The staining is probably mainly in the inflammatory cells. In contrast to some H&N SCC they are negative for EBV studies and I suppose it's always worth considering the possibility of a metastasis from an underlying primary in the H&N in particular.