Case Number : Case 1556 - 13 June Posted By: Guest

Dermal Duct Tumor

I agree with dermal duct tumour, as the cells look poroid, on the condition that ducts are demonstrated by immunohistochemistry. 

Agree. Can't see ducts on H&E, but very poroid looking cells.

I think better categorised as a poroid hidradenoma, in view of lack of connection to surface and absence of obvious ductal differentiation.

I find this lesion very odd. No ducts although agree poroid-like.  I see foci of subtle bowenoid dysplasia (including individual cell necrosis and atypical mitotic figures) developing into confluent parakeratosis. Profile is reminiscent of pilar sheath acanthoma. Could it be bowenoid changes within pilar sheath acanthoma? On second thoughts a low-grade hidradenocarcinoma is also a possibility.

To be honest my first impression was that of a neoplasm with predominant follicular differentiation. We have small cells poroid like with abrupt keratinization and calcification, individual apoptosis, some mitotic figures. There are some pictures where the cells look with a bit more cytoplasm and clearer. I actually thought that the suggestion  of the referring pathologist was quite good I think this is a lesion in the spectrum of proliferating trichilemmal tumor.

I think there isn't any follicular differentiation, but a very ductal/poroid differentiation! May be i'm wrong but in Fig5/6/7/8 i see a ductal-cystic differentiation and the cells are too poroid...

I think there isn't any follicular differentiation, but a very ductal/poroid differentiation! May be i'm wrong but in Fig5/6/7/8 i see a ductal-cystic differentiation and the cells are too poroid...

Look at the last picture, the cells look ORS like, there is individual cell apoptosis, and on the left side of the picture there is abrupt keratinization and there are some granular layer like vestiges (variable size keratohyaline granules). I dont know it really looks like the neoplasm has follicular differentiation to my eyes