DCIS and Lobular Neoplasia

Had stereotactic biopsy which found DCIS and lobular neoplasia in left breast.  Had lumpectomy and surgical pathological report indicated only the lobular neoplasia and atypical ductal hyperplasia, but no residual DCIS.  All margins were clear from 1cm up to 4 cm and 4 sentinel lymph nodes were also clear.  Surgeon took out a large specimen (6cm x 4cm) to make sure he got it all and that margins were clear.  Is it unusual for DCIS to be found on biopsy, but not on specimen from actual lumpectomy?  Also, what are considered acceptable margins for tissue findings?

[japdip]

I'm not sure why the DCIS wouldn't be found in the specimen unless that specific area escaped being tested in the Path. Lab. Acceptable margins are usually 2mm and sometimes even a 1mm margin is OK.  Regards ....

[LadyTE]

My surgeon said that sometimes all of the existing DCIS is removed in the biopsy, which may have been the case with me.  Thanks for the info on acceptable margins.  Makes me feel better ,since the smallest clear margin I had was 1 cm and the largest was 4 cm.  From what the pathology report said, they thoroughly examined the entire specimen and found no residual DCIS, just the aytypical ductal cells, which is often a precursor to DCIS.  All of this was found in only a central portion of the specimen, in a small lesion that measured less than 1 cm.  Rest of tissue was determined to be without any pathological findings.