Case Number : Case 1585 - 22 July Posted By: Guest

Sebaceous Carcinoma?

Or Balloon cell Melanoma, pseudolipoblastic type?

Doesnt have the germinative/basaloid element for sebaceous carcinoma. Balloon cell melanoma is a good possibility. Other d/d of clear cell tumours including metastatic RCC need to be excluded. Needs a wide panel of immunos...awaiting aditional images!

I really enjoyed catching up with this week's cases after our hospital internet was down most of the week.  Arti's case spectacular (I want a copy section!).  Can I suggest checking out Case 552 (one of mine) and Case 1378 for those who want to revise lipomembranous fat necrosis.  I have started using google to search Dermpathpro cases to good effect!  Warm regards to all.

Agree, needs a wide IHC panel. Would add an atypical lipomatous tumour to the list.

Agree need immunos, I think my favourite choice is melanoma with balloon/clear cell change. There is some cytoplasmic retraction in some cells and sclerosis so just to throw a more exotic option could consider an atypical Pecoma.

Ofcourse Richard, will send a copy section next week...  

Thanks Dr Richard!!!

Pleomorphic liposarcoma?

Balloon cell melanoma

Yes, balloon cell melanoma.

Yes very well done to all.

I think these are an admixture of balloon cells (very low nuclear to cytoplasmic ratio), intermediate and sebocyte-like malignant melanoma cells (higher nuclear to cytoplasmic ratio according to the definitions in the paper by Kazlouskaya et al Am J Dermpath 2014;35:380-386.  I recommend you also read a fascinating little piece yet to come in the printed journal by Dr Resnik, Am J Dermpath, "Sebocyte-like melanocytes - Additional relevant (and behind the scenes) historical information. I'm pretty sure sebocytes-like and balloon cells are merely ends of a spectrum as suggested by Kazlouskaya et al.

It seems sebocyte-like cells in melanoma is in any case very rare.  In this case the clear cells only made up about 10% of the melanoma but they were quite striking.

Yo! to all 

[you have to read Resnik reference to understand this sign off].