Case Number : Case 2956 - 04 November 2021 Posted By: Saleem Taibjee

I am torn between pigmented actinic keratosis and melanoma-in-situ mainly because of lack of expertise as we rarely see these cases in India. IHC for melanocytes will help. 

PIgmented AK/early SCCIS. Would get a MART-1 or SOX-10 just to rule out MMIS.

Pigmented Actinic Keratosis

I think the dysplasia and dyskeratosis  are rather too much for a solar keratosis.  Also the parakeratotic hyperkeratosis is more suggestive of a keratinocyte dysplasia than melanoma.   I would call this pigmented Bowen's disease.

However, I would agree that it would be prudent to do MART-1 or SOX.

SCC in situ

Looks like clonal lesion- my differentials Bowens and MM (pigment dropping down , macrophages with pigment -according to Akerman it is can be clue to MM)

A lot of sun damage under the lesion 

I would want to do p16, p53, Melan A

actinic keratosis

Here are the immunos which help clarify .....

Yes, well done. As confirmed by the immunos, this is a nice example of pigmented and pagetoid Bowen's. The p53 is particularly impressive.

BW

Saleem