Case Number : Case 2668 - 28 September 2020 Posted By: Iskander H. Chaudhry

I don't know what this is, and it seems no-one else is sufficiently confident about the diagnosis to venture a comment, so I'll start the ball rolling.  This lesion shows a sclerotic stromal reaction around islands of basophilic cells, some of which are originating from the epidermis.  In places there are cells which look trichilemmal, suggesting a desmoplastic trichilemmoma.  However, I see also areas where the cytology looks more poroma-like.  I'm not sure what to make of the elastic tissue alteration which is highlighted in figures 4,6 and 8.  I look forward to seeing what others make of this.

solid carcinoma / solid variant of microcystic adnexal carcinoma.

?Desmoplastic trichoepithelioma

Please Dr Iskander: what’s the 2658 and 2664 dx?

Agree with ?DTE. 

Solid variant of microcystic adnexal carcinoma.

Thank you all - on this biopsy with the crust artefact the two main differentials are desmoplastic trichoepithelioma versus a micronodular basal cell carcinoma. We gave the differential but requested a complete excision. Microcystic adnexal carcinoma would typically show the BM thickening and cribriform architecture and is very rare in the skin. 

Iskander H. Chaudhry 

On 30/09/2020 at 18:46, vincenzo said:

Please Dr Iskander: what’s the 2658 and 2664 dx?

Agree with ?DTE. 

These now have comments attached thanks 

IHC can be quite useful for this sort of thing. I was wondering about a low grade carcinoma like MAC (not ducts in the images). It looks low grade and indolent.