Case Number : Case 2627 - 31 July 2020 Posted By: Dr. Richard Carr

Melanoma. 

Of course melanoma should be excluded, but I also thought of atypical cellular neurothekoma? Definitely needs IHC. 

I would also consider cellular neurothekeoma. There are also seems to be some biphasic pattern under low magnifciation, with peripehral light areas and central dark zone, which makes me include myofibroma as a differential.  IHC needed. 

clear cell sarcoma

My first thought goes with Clear Cell Sarcoma, 2º choice Clear Cell Melanoma. Same IHC but CCS has t(12;22) (q13;q12): chimeric EWSR1/ATF1.

?Clear Cell BCC...

Merkel Cell Carcinoma could be BerEp4+ also, but it’s usually EMA+  

Maybe some myoepithelial markers.

This is a clear cell BCC with desmoplastic tricholemmoma-like features. The combination of moderately strong BerEP4 and COMPLETELY NEGATIVE EMA in the BASALOID epithelium is practically pathognomic of BCC. I did not do melanocytic or myoepithelial markers after seeing this IHC pattern. You can see focal CD34 in these types of BCC (not in this one). BerEP4 can be reduced in clear cell BCC and the EMA, completely negative in the BASALOID component is very typical for BCC in such cases.

I've added to the discussion in last weeks case following Anh's helpful points.

Sir no words, thanks a lot for this case