Does finding a positive surgical margin containing pleomorphic LCIS in a patient with early-stage invasive ductal carcinoma of the breast affect your management in regards to breast conservation therapy?

Based on limited data, we treat PLCIS with the same principal as DCIS and aim for a negative margin and offer adjuvant RT. PLCIS presents with microcalcs like DCIS and in the pre e-cadherin staining era, they were called DCIS and included in the old NSABP study as DCIS.

There is much confusion about pleomorphic LCIS, how it is classified, and how it should be treated. It has been suggested that it behaves more like DCIS and therefore should be treated as such. Some have advocated that even for a diagnosis of strictly pleomorhpic LCIS, it should be excised and irradiated as if it were DCIS.

Given the uncertainties, if a pathologist indeed referred to LCIS at a margin as pleomorphic LCIS, I would be inclined to re-excise if possible prior to irradiation. If it was more routine LCIS (not pleomorphic) at the margin, although there is some conflicting literature, I tend to not ask for re-excision and proceed directly to radiation.

Bear in mind that there is not much in the way of evidence based literature to ...