Case Number : Case 2462 - 10 December 2019 Posted By: Uma Sundram

infiltrative BCC

can  we have BerEP4. IHC

I think that this is a basal cell carcinoma which shows features of infiltrative pattern, fibroepithelioma of Pinkus and in one field syringocystadenoma papilliferum like differentiation. 

Syringocystadenocarcinoma papilliferum.

AGREE WITH BCC...infundibulo-cystic type. 

BEREP4 is negative. Any thoughts other than BCC?

Sorry, I note the diagnosis of syringocystadenocarcinoma as well.

? SCC arising from syringocystadenoma papilliferum.

Looking at images 2,3,5, and with the information of negative BEREP-4, I am thinking in basaloid SCC, but honestly I can not understand the orientation of image 4! Putting it with image 1, may be the tumor is arising in a cyst?! 

?Hidroadenocarcinoma ( malignant hidroadenoma papilliferum )...

The problem is: this lesion is malignant, so I can't think of a desmoplastic trichilemmoma...and trichilemmal carcinoma is a dark entity for me...but I'd like this diagnosis!!!

12 minutes ago, vincenzo said:

The problem is: this lesion is malignant, so I can't think of a desmoplastic trichilemmoma...and trichilemmal carcinoma is a dark entity for me...but I'd like this diagnosis!!!

Had the same thoughts too!

Very difficult. The basaloid tumours seems to have a specialised stroma so I suppose we could consider a true trichoblastic carcinoma / trichoblastoma (mitotic++ but odd infiltrative-like growth) I'd also expect at least some BerEP4 staining. I think EMA is important here. If it's completely negative BCC with negative BerEP4 is back on the agenda. Could add CD10 for stromal condensations and CK20 for reactive merkel cells (in trichoblastoma). 

p53 and p16 might be useful if they show a null or a diffuse positive (supports malignant diagnosis). Agree the other cystic part does look like syringocystadenocarcinoma again the p53 and p16 & Ki67 might help with that and a p63 (for the myoepithelial layer. Nice challenge would like to see the glass! There is follicular pseudoepitheliomatous hyperplasia here. 

BTW please check out my case from last friday: Clinical & dermoscopic images.

Case 2455 is also open / undiagnosed from 29/11/19.

Well, I'm glad I wasn't the only one challenged here! I have been having some trouble posting on my account, so apologize in advance for the tardiness in posting. EMA is negative so I did include BerEP4 negative BCC in my differential (common things being common). p53 was positive and Ki67 was relatively high, so I did not think of something benign. I was also intrigued by the cystic component so I did think of both syringocystadenocarcinoma as well as hidradenocarcinoma. Importantly, I alerted the clinician about the possibility of hidradenocarcinoma (I think the most likely fit, with pseudoepitheliomatous hyperplasia), since they can be more clinically aggressive than a typical (albeit unusual) BCC. We did go around and around about lineage though!