Case Number : Case 1528 - 03 May Posted By: Guest

I think this is a syringolymphoid hyperplasia-like intraepidermal growth, with subtle sebaceous differentiation and atypical cells. there is some pagetoid spread. Favour a sebaceous carcinoma in situ, with lymphoid reaction.

I find this biopsy rather hard for interpretation. I think there are a lot of reactive changes due to the dense lymphocytic infiltrate but I am not 100% sure that the lesion is in situ (mainly due to the marked desmoplasia seen). I considered pagetoid Bowen alone or associated with invasive SCC as well as porocarcinoma (even if the cells dont look that poroid to my eyes) in my differentials. I would perform CK7 and CEA that could help in this distinction but I favor an squamous origin to this lesion. Sincerely I did not have the impression that the cells could have a sebaceous nature but who knows...

Looks like an incisional biopsy, appearances of Bowen's. The latter is adnexotropic. Like Raul has suggested would consider an in-situ porocarcinoma. Was there an invasive SCC adjacent to this ?

Tricky because so inflamed.  I was thinking may be adnexotropic bowenoid actinic keratosis with focal pagetoid bowen's.

Favour Bowen's.  CAM5.2, BER and EMA to confirm.  (CAM5.2/BER +ve and EMA -ve in sebaceous neopasia in-situ and CAM5.2/BER/EMA +ve in glandular neoplasia in-situ.) 

This was indeed a difficult case. It was a de novo lesion with no adjacent invasive squamous cell carcinoma. I had a differential diagnosis of adnexal/glandular carcinoma versus sebaceous carcinoma; an invasive component may be present. BerEp4 is positive but faint, EMA is positive, and CK7/CAM5.2 were both positive. Needless to say we recommended a re excision. It's a relatively new case and I will give follow up if I get it.