Case Number : Case 2214 - 4 December 2018 Posted By: Uma Sundram

My impressions are Basalod SCC vs Sebaceous Carcinoma. I favor the first.

Basal cell carcinoma.  Could be a manifestation of nevoid basal cell carcinoma syndrome as the site of the lesion and mental retardation of the patient suggest. 

looks like sebaceous gland carcinoma with intraepithelial spread and dermal invasion. because of the basaloid component could be a sebaceous epithelioma change to adenocarcinoma. the tumor is in area other than head and neck and cystic changes are seen in tumor. I would like to rule out Muir torr syndrome, may be get some IHC done for loss of MSH-6 expression 

I also favor basaloid SCC.

I would like to favour Basaloid Squamous Cell Carcinoma. So, Dr. Uma Sundram wath was the final diagnosis?

I favor extra ocular poorly differentiated sebaceous carcinoma.  Vulva is a well known extra-eyelids site.  This is a fully malignant neoplasia, instead BCC with sebaceous differentiation ( if does exist ), is a conventional BCC ( epithelial-stromal retraction, periepithelial mucin, peripheral palisading, mild/moderate atypia ). Muir-Torre syndrome?

My first impression was a basaloid SCC, but the last 2 pictures show sebaceus differentiation that make us suspect of sabaceous carcinoma. IHQ with adipophilin and Factor XIIIa can be of great help. If we confirm the diagnosis, investigation of Muir Torre syndrome is necessary.

Apologies, fellow spot diagnostic friends, for the delay in posting. An excellent discussion.

We too were between basaloid SCC and sebaceous carcinoma. Adipophilin was positive only in the sebocyte areas, leading us to favor this less. It may have been involvement of a pre existing sebaceous unit by carcinoma. All 4 MSI proteins were expressed with no loss. I did not favor BCC for the reasons already elaborated by the other wonderful posts here.

Stay tuned for next weeks post -- I promise to be on top of it this time! The holiday rush in the US is leading to a LOT of skin biopsies :)

good discussion