Case Number : Case 4069 - 25 August 202 Posted By: Saleem Taibjee

Trichoepithelioma

Combined adnexal tumor: left easier: trichoblastoma. Right...thinking of an apocrine benign tumor...?apocrine adenoma. But I don’t see enough papillary changes. 

Trichoblastoma on the left, apocrine cystadenoma on the right.

Agree, TB on the left, a benign eccrine/apocrine tumor on the right. Not sure what the best name for it is. The collagenous stroma raises the possibility of a hidradenoma with apocrine differentiation?

Trichoblastoma + tubular adenoma.

Yes, well done. I too concluded that this is a combination of trichepithelioma and tubular apocrine adenoma (debatable nomenclature). A rather curious and unique recent case!

A couple of the immunos are shown below (requested more for interest, but not altering the impression on H&E). The CEA nicely highlights the ducts in the glandular component, and the CD10 highlights the papillary mesenchymal cells in the trichoepithelioma.

BW
Saleem