I am a RN with 35 years nursing experience, and I had an excisional biopsy myself last month. The terms mean pretty much the same thing. Technically, a lumpectomy is simply the removal of a lump. In an excisional biopsy, the lump is removed as well as a portion of healthy tissue surrounding the lump. The terms clear, clean, or negative margins all mean that no suspicious cells were close to the edge of the excised tissue. In other words, they got it all. Close margins means suspicious or cancerous cells were close to the edge of the excised mass, and positive margins would mean that suspicious or cancerous cells were all the way to the edge of the excised tissue. In those incidences you would go back to surgery so they could take out a little more.