Case Number : Case 3032 - 18 February 2022 Posted By: Dr. Richard Carr

Peri-tumoral spindled stroma, stromal-stromal cleft, lack of mucin; in keeping with small nodular trichoblastoma.

A nice Saint Valentino trichoblastoma?

4 hours ago, vincenzo said:

A nice Saint Valentino trichoblastoma?

To the point!

can we consider micro nodular variant of BCC. considering the age of the patient. How to rule out  Dr Carr. also the nodules are going deep

Trichoblastoma. But I would do some immunostains. I like to use CK20 and androgen receptor. In some cases I like to add ki-67 or bcl-2 as well.

This a [LOVE-LY] small nodular trichoblastoma. It really is an H&E diagnosis (but my favourite IHC would be CD10 to highlight the papillary mesenchymal cells - not needed in this case and CK20 for reactive Merkel cells - but only about 30% sensitive for TB - beware traped MC in vellus follicles on the face etc. but BCC in my experience don't have them). I did Bcl2 a bit and found it unhelpful, same for CD34. On the central face these lesions can be very deep (they are indolent and keeping growing). One group even suggested they should be considered as low-grade carcinoma due to the deep "invasion" at this location but I found the argument weak. Obviously Moh's surgery can be a good approach if the lesion is deeply extending (even into the muscles of the face).  I normally say "Lesions can grow to large size but malignant transformation is rare." I'd recommend complete excision if asked and that goes for nearly all mitotically active "benign" skin tumours (other than typical KA and pilomatrixoma).

Thanks a lot sir for the useful tips