Case Number : Case 1656 - 31 October Posted By: Guest

Here is Richard's Hallowe'en treat for you all, just a little early as I am away in Paris until Monday evening. My lovely daughter Martha will be adding a number of images at 6pm on Monday afternoon.

Cheers, Geoff

Carcinosarcoma 

Sarcomatoid SCC is my first impression for IHC. 

agree sarcomatoid/spindle cell squamous cell carcinoma

Sarcomatoid squamous cell carcinoma is also my first thought. Neoplastic spindle cells seem to be released from the epidermis.

Agree with spindle cell SCC, above all in fig 4/5. Fig 6 make me thing to a melanoma...but my spot diagnosis without IHC is SCC.

I think of spindle cell SCC,too. The neoplasm seems to attach to overlying epidermis.

Although Spindle melanoma is also in differential.

IHC study at least for cytokeratin,S100 ,melanA  are indicated.

Spindle cell SCC for verification by immunos cytokeratin, S100, MelanA, desmin. 

Lovely immunos.

Sarcomatoid SCC is confirmed inspite of CD10 positivity (characteristic of AFX) as pan keratin and P63 also are positive

nice related article:

https://www.ncbi.nlm.nih.gov/m/pubmed/21883368/

Agree, sarcomatoid SCC.

Yes, sarcomatoid SCC. Also shows the non specificity of CD10!

 Richard, how does a p53 help in this setting?

Yes well done all - very good!  This is sarcomatoid carcinoma (presumed a variant of cutaneous SCC).

Thanks for the question about p53 which was the point of the case.  Saleem Taibjee drew my attention to it's use for margins in AFX/AFX-type cutaneous sarcoma (the latter my preferred designation for lesions that are either dermal and not circumscript or in which there is clear-cut invasion of subcutis - I am not a fan of so-called "pleomorphic dermal sarcoma" designation on several levels). p53 when diffusely strong can help with assessing margins for the "superficial spreading variant" that I have seen several times and on one or two occasions recurring (this is not in the text-books). However CD10 (a much maligned antibody IMHO) has been doing this job for me for a long time quite adequately actually and is far more sensitive, I also believe diffuse CD10 is pretty specific for AFX (we've collected over a 100 cases). In this case CD10 was ++40% (mainly interstitial, presumed reactive, cells).  To repeat my approach to this DDx I use a very limited panel S100 only (for melanoma), Pan-keratin & p63 (for carcinoma) and CD10 (diffuse supports AFX/AFX-type cutaneous sarcoma). I'm experimenting with p53 right now but will probably drop it soon I suspect.  I only add CD30 and vascular markers as required by morphology although a spindle cell variant of angiosarcoma can be a catch it is exceedingly rare.  I don't worry about cutaneous leiomyosarcomas at all at the treatment & prognosis for them is the same as AFX/AFX-type sarcoma.

Thanks Richard, very useful! I remember seeing a case of 'superficial spreading' AFX in your collection and the degree of horizontal spread of the tumour is easily missed.