Case Number : Case 2604 - 30 June 2020 Posted By: Uma Sundram

MAC

Difficult for me. MAC is a good differential. ?An odd MAC, mostly solid and ductal type, without follicular (keratinous) cysts. Or ?a Squamoid Ductal Carcinoma, given my impression of some atypias in last pic. 

As a non-pathologist I am struggling with this. It is clearly an infiltrative malignant tumour.  The growth pattern looks very squamoid from the epidermis, but more basaloid deeper down and there appears to be mucin in the stroma as well.  Obviously the ductal structure has to be accounted for.  It doesn't look like a typical MAC, but I can't explain it any other way.  Looking forward to hearing the final diagnosis.

Eccrine ductal carcinoma?

Eccrine Differentiation in Basal Cell Carcinoma 

I like all of your assessments. MAC would be unusual, because it is relatively superficial and shows cytologic atypia. Eccrine ductal carcinoma and BCC with eccrine differentiation are good thoughts. We were unfancy w this one, and called it early invasive SCC. It's on the eyelid and the surgeon had clear margins. I think the pictures make the tumor look more basaloid than I initially thought.

I mean this tumor is more superficial than a typical MAC, and shows more Cytologic atypia.

Thanks Uma. These are very useful cases.