Case Number : Case 1012 - 9th May Posted By: Guest

Large basaloid tumour with rippled pattern. Ductal differentiation. I think i see sebocytes also with indented nuclei. Very pink?, ?matrical differenttation. I also wondered if there was background nevus sebaceous but not sure about that. I would think about requesting a BerEP4 and EMA to start with and my working diagnosis is this is a sebaceoma, rippled pattern with ductal differentiation. DDX rippled pattern BCC with duactal and sebaceous differentiation (which would be very rare)

I did think there was a carcinoid-like (rippled) architecture in the upper right image, but I didn't think there was sebaceous differentiation. My first thought was basaloid hidradenoma. Would EMA differentiate between hidradenoma and sebaceoma?

To me, the first impression with the large basaloid tumor, deep in the dermis, with ductal differentiation and esinophilic hyaline deposits (fig 4 and 5) and trabecular pattern, was spiradenoma. However the lack of dual cell population in some areas, lack of lymphocytes within the tumor and the presence of some nuclear pleomorphism, prominent nucleoli and ? mitoses (fig 2 and 3), made me think of the possibility of low grade spiradenocarcinoma developing within a pre-existing spiradenoma. An overlapping spiradenoma/cylindroma as an origin is also possible. Interesting case. Anxious to know the correct diagnosis!!!!

Spiradenocarcinoma vs BCC with adnexal differentiation.

IHC will be posted at 4pm British Summer Time

[img]https://dermpathpro.com/uploads/spot_diagnosis_comment_img/CASE1012_%20RAC6814x10_EMA_Label.jpg[/img]

[img]https://dermpathpro.com/uploads/spot_diagnosis_comment_img/CASE1012_%20RAC6814x10b_CEA_Label.jpg[/img]

[img]https://dermpathpro.com/uploads/spot_diagnosis_comment_img/CASE1012_%20RAC6814x20_PASD_Label.jpg[/img]

[img]https://dermpathpro.com/uploads/spot_diagnosis_comment_img/CASE1012_%20RAC6814x40_EMA_Label.jpg[/img]

[img]https://dermpathpro.com/uploads/spot_diagnosis_comment_img/CASE1012_%20RAC6814x5_BerEP4_Label.jpg[/img]

BCC with ductal differentiation, as Dr El-Nabarawy suggested.

So it is BCC with ductal differentiation... Lovely one as usual Dr Carr...

[font=Arial, sans-serif][size=4]Basal cell carcinoma with areas showing organoid pattern and focal ductal differentiation with squamoid lining.[/size][/font]

Agree with BCC with eccrine differentiation.
The ductal areas show dual positivity with EMA and CEA with some showing hylaline eosinophilic linings (sebaceous would be CEA negative). The basaloid cells are EMA negative and BER-EP4 positive, and have scattered mitotic activity.

Wouldn't rule out a coexistent progenitor trichoblastoma if this was a nevus sebaceus background (as Nick suggested).

Well a great case (yes BCC with striking ductal differentiation) even if I say so myself and great responses today. I think you have all made my points for me. Remember ductal differentiation is not that uncommon in BCC. This one was a referred slide with rather pale haematoxylin so the mucin in the stroma of the third image cannot be easily made out and palisading is rather pathetic. I have not yet come across rippled hidradenoma or rippled spiradenoma (remember I used the rippled pattern recently to favour sebaceoma v hidradenoma). The EMA is very helpful as the lumens should be punched out in hidradenoma / ductal differentiation (as in this BCC) whereas we like to see multiple intra-cytoplasmic vacuoles indenting the nucleus on EMA in true sebaceous differentation (exceedingly rare in BCC although I do have 3 cases collected). CEA can be nice for ductal differentiation but is often not sensitive and it does stain squamous cells rather non-specifically. I am not too sure what the dull, lightly PASD positive globular material is - but maybe a keratin derived cuticular type material? Finally we do not have papillary mesenchymal cells for rippled pattern trichoblastoma. There was a low grade mitotic rate and apoptotic cells (not shown well in these images) so I was happy after seeing the BerEP4 to confirm my favoured H&E diagnosis of BCC with ductal differentiation. In my experience rippled pattern BCC is very rare (only collected two or three). Regards to all and enjoy your weekends.