Case Number : Case 3062 - 01 April 2022 Posted By: Dr. Richard Carr

?Proximal type ES?

Great job Vincenzo. INI1 was absent. I found this case very difficult but we concluded small epithelioid sarcoma (having pretty much excluded every other possibility). I the shared case with Raul Perret, Thomas Mentzel and Chris Fletcher who all agreed. Lesion had already been re-excised with no residual tumour so watchful waiting was advised. Given small size unlikely to behave aggressively (finger crossed). This is the first epithelioid sarcoma I've seen in 20+ years of busy skin reporting and referral practice so to see a tiny example like this in the vulva was quite a challenge diagnostically but we got there in the end. p63 negative / epithelial markers positive was the big clue and of course it does look vaguely granulomatous. All myoepithelial markers were negative including (S100, Sox10, GFAP) and EMA was diffusely positive. CD34 negative in this instance. 

References c/o Raul Perret:

Yoshida A, Yoshida H, Yoshida M, Mori T, Kobayashi E, Tanzawa Y, Yasugi T, Kawana K, Ishikawa M, Sugiura H, Maeda D, Fukayama M, Kawai A, Hiraoka N, Motoi T. Myoepithelioma-like Tumors of the Vulvar Region: A Distinctive Group of SMARCB1-deficient Neoplasms. Am J Surg Pathol. 2015 Aug;39(8):1102-13. doi: 10.1097/PAS.0000000000000466. PMID: 26171919.

Folpe AL, Schoolmeester JK, McCluggage WG, Sullivan LM, Castagna K, Ahrens WA, Oliva E, Biegel JA, Nielsen GP. SMARCB1-deficient Vulvar Neoplasms: A Clinicopathologic, Immunohistochemical, and Molecular Genetic Study of 14 Cases. Am J Surg Pathol. 2015 Jun;39(6):836-49. doi: 10.1097/PAS.0000000000000397. PMID: 25651469.

Forgot to say although the lesion is "proximal" it does not have the high grade features of a "proximal-type" ES. (Raul reminded me).

Thanks very much Richard, but above all I’ll have to thank you for all the opportunities you offer us all to grow in dermpath and surgical pathology. 

Dear Vincenzo,

I will put that snippet in my appraisal folder! You, along with anyone interested in extending their dermatopathology, are welcome to visit. There are now close to 8,000 glass slides in my teaching archive and I'd guess over 5,000 are skins and soft tissues. Anyone studying for the international or RCPath expert diploma in skin are particularly welcomed.