Case Number : Case 2736 - 31 December 2020 Posted By: Saleem Taibjee

For my last throw of the dice at the end of a year we'll all be glad to see the back of:

Neuroendocrine carcinoma. 

Some New Year immunohistochemistry awaited with bated breath!

Happy New Year everyone.

Happy New Year !

agree with De Logan, it is consistent with Merkel Cell carcinoma, I can see some scattered similar cells in the epidermis. The chromatin is nice “ salt and peppers” neuroendocrine looking.  Question for the group discussion: how often do you do the Merkel cell polyomavirus test? Is it required nowadays for prognosis purpose?

?Melanoma, with angiolymphatic infiltration ( second and last fig. 

I'm not sure that the images uploaded that well initially. Hence see below.

Looking at these images I'm now less inclined towards a diagnosis of Merkel cell carcinoma.  The tumour cells have an eosinophilic cytoplasm and show vacuolation.  The last image shows intravascular spread.  Is this a metastatic SCC or suchlike?

Happy New Year!

This is a recent case of amelanotic melanoma. The Melan-A shown below. The main reason for sharing it is that the intravascular micrometastasis was very subtle and could have been easily missed, especially during a busy sign out session. This is rather uncommon scenario in my experience, and of course, connotes a worse prognosis/upstaging.

Of course, the patient will undergo re-excision as per guidelines, but one is unsure whether this really affects the prognosis or outcome because in effect the disease is already 'metastatic'. For those that have not already read this excellent article by Wolfgang Weyers, I suggest reading Personalized Excision of Malignant Melanoma—Need for
a Paradigm Shift in the Beginning Era of Personalized Medicine in Am J Dermatopathol 2019;41:884–896.

BW, Saleem