Case Number : Case 2109 - 6 July 2018 Posted By: Dr. Richard Carr

The lesion in the epidermis looks like a dilated pore of Winer. The dermis shows a foreign body granuloma possibly around suture material remnants from a previous surgery.

10 hours ago, Anil Patki said:

The lesion in the epidermis looks like a dilated pore of Winer. The dermis shows a foreign body granuloma possibly around suture material remnants from a previous surgery.

...or a synus pilonidalis if in sacral area

New images added!

?DFSP with epidermal cystic induction. Waiting for the final diagnosis...

I was considering a dermatomyofibroma.  But staining weird.  The lesion on H&E didn’t seem classic for DFSP.  A bit less cellular and not pinwheel.  The CD 34 is pretty diffuse at the base, though which speaks against DMF and SMA is only focal. Plaque stage DFSP? I’m really not sure about this one.  The cyst could be separate process.

Dual pathology - FB granuloma and DFSP.

I still think it's just a scar to a ruptured cyst. But now that the immunos were done, every pathologist would be worried.

This is not DFSP. There is a scar, granulomatous inflammation and a dilated follicle but no neoplasm here

Thanks for all the responses. This appeared to be a straightforward reaction to a previously ruptured epidermoid cyst or comedone.  I was a little perturbed by the slightly lace like hypercellular process involving the subcutis, resemblind DFSP. I thought the SMA was commensurate with the more cellular active myofibroblastic proliferation in the scar and peripheral CD34 probably reflecting more mature scarring. The loss of elastic supported scarring rather than and DFSP (or dermatofibroma) which in my experience have well preserved if not accentuated elastic staining. Apologies for the late post. I had a computer crash last week and have been on hols. We're walking the dog in Ayreshire, Scotland.

On 16/07/2018 at 11:39, Dr. Richard Carr said:

Thanks for all the responses. This appeared to be a straightforward reaction to a previously ruptured epidermoid cyst or comedone.  I was a little perturbed by the slightly lace like hypercellular process involving the subcutis, resemblind DFSP. I thought the SMA was commensurate with the more cellular active myofibroblastic proliferation in the scar and peripheral CD34 probably reflecting more mature scarring. The loss of elastic supported scarring rather than and DFSP (or dermatofibroma) which in my experience have well preserved if not accentuated elastic staining. Apologies for the late post. I had a computer crash last week and have been on hols. We're walking the dog in Ayreshire, Scotland.

Brilliant as usual :-)