Question: I am 52 years old, no family history of breast cancer, and I have started getting yearly mammograms. My doctor found some new calcified areas in my breast and biopsied them. The report said I had “ductal carcinoma in situ, low nuclear grade, solid type without necrosis.” The calcium was apparently in the carcinoma. My doctor told me I needed to have surgery to remove all of the area around this spot but I wasn’t sure I wanted that. I went to another doctor for a second opinion and they said I didn’t have ductal carcinoma in situ I had lobular carcinoma in situ and I didn’t need to have surgery?!

Answer: I have seen this before where one pathologist calls something ductal carcinoma in situ (DCIS) and another calls the same biopsy lobular carcinoma in situ (LCIS). As frustrating as it may be, this is not completely uncommon and it is because some cases of DCIS can look like LCIS under the microscope.

There is a special study a pathologist can perform called immunohistochemistry using an antibody called e-cadherin which is absent in MOST but not all cases of LCIS. I could not tell from your question whether that study was done on your biopsy by either of the pathologists but that may be why the second pathologist changed the diagnosis to LCIS.

The issue now is which doctor do you feel is correct? It is correct that if you have a diagnosis of DCIS on a core biopsy you need to have surgery to try to remove the entire area, but it is still somewhat controversial as to whether LCIS on a core biopsy needs to be surgically excised. So it is important to find out from the pathologist why the diagnosis was changed to LCIS and if need be you might want to get another opinion to confirm that before deciding on your next plan of action.