Case Number : Case 1885 - 18 August - Dr Richard Carr Posted By: Guest

the superficial component connected to epidermis looks like a basal cell carcinoma. the depper component is morphologically different with some glandular/pseudoglandular areas, keratin plugs, some signet ring like cells. ? some variant of BCC ? some type of eccrine carcinoma.

Concomitatnt BCC and MAC

Trichoepithelioma-like BCC

Agree with concomitant superficial BCC and MAC. 

Berp4, EMA among other stainings could help to see if they are neoplasms originated from different clones

My first impression also was collision between basal cell carcinoma and microcystic adnexal carcinoma, but the mitotic activity is too high and the nuclear morphology is not so bland as would be expected for that sweat gland tumor. Although microcystic adnexal carcinoma may rarely present high-grade features, my sense is this whole lesion is a basal cell carcinoma with micronodular growth pattern, a variant that may lack retraction clefts, and exhibit ductal and squamous differentiation.

The Mona's suggestion is a good differential. However, according with Robledo, this is a high grade malignancy, so what about a metastasis of lung carcinoma, with an odd induction effect?

Collision. I thought about infundibular cystic bcc but it looks like the cells and layers of maturation of a Mac. And good site. That's my first thought before stains

17 hours ago, Dr. Mona Abdel Halim said:

Concomitant BCC and MAC

Agree

Many thanks for all your comments. My final diagnosis was:

Collision of BCC and infiltrative, pseudoglandular, follicular squamous cell carcinoma.