Case Number : Case 2775 - 24 February 2021 Posted By: Iskander H. Chaudhry

Sebaceous neoplasia

Need excision to rule out malignancy

Sebaceous tumor. I would favor sebaceoma, but full excision is required in order to properly assess the architecture.

I suspect this is a porocarcinoma.

Sebaceoma for me

There are too mitosis for a sebaceoma, but favor this diagnosis. 

I will go with sebaceoma. 

Sebaceoma

Thank you everyone. Yes, interesting discussion. This is a sebaecous tumour and the question is sebaceoma versus well diff seb carcinoma. I accept porocarcinoma is in the differential but I felt there was definite sebaceous differentiation. You can see increase mitotic activity in a sebaceoma, however, this is typically spare. Stigmata for carcinoma are prominent nucleoli, mitotically activity and pleomorphism - necrosis is a helpful feature. Deep extension, adnexal or lymphovascular invasion are all seen in carcinoma. 

This was reported as favouring an extra-ocular well differentiated sebeacous carcinoma.