what does my pathology report mean

I think that the following might help answer your questions about what these things refer to - as far as the 'prognosis' is concerned, this information from your pathology report wouldn't give anybody the ability to determine that. Sorry about the big type - was just cutting and pasting.

What is infiltrating or invasive?

These words are used to mean that the cancer is not a pre-cancer (or in-situ), but is a true cancer.

The normal breast is made of ducts that end in a group of blind-ending sacs (lobules). Cancer starts in the cells lining the ducts and lobules, when a normal cell becomes a carcinoma cell. As long as the carcinoma cells are still confined to the breast ducts or lobules, without breaking out and growing into surrounding tissue, it is considered in-situ carcinoma. Once the carcinoma cells have grown and broken out of the ducts or lobules, it is called invasive or infiltrating carcinoma. In an invasive carcinoma, the tumor cells can spread (metastasize) to other parts of your body.

What does it mean if my carcinoma is well differentiated, moderately differentiated, or poorly differentiated?

When looking at the cancer cells under the microscope, the pathologist looks for certain features that can help predict how likely the cancer is to grow and spread. These features include the arrangement of the cells in relation to each other, whether they form tubules, how closely they resemble normal breast cells (nuclear grade), and how many of the cancer cells are in the process of dividing (mitotic count). These features taken together determine how differentiated the cancer is (and its grade – see below).

Well-differentiated carcinomas have relatively normal-looking cells that do not appear to be growing rapidly and are arranged in small tubules for ductal cancer and cords in lobular cancer. These cancers tend to grow and spread slowly and so have a better prognosis (outlook).

Poorly differentiated carcinomas lack normal features, tend to grow and spread faster, and have a worse prognosis. Moderately differentiated carcinomas have features and prognosis in-between these two.

What is histologic grade or Nottingham grade or Elston grade?

These grades are similar to what is described in the question above about differentiation. Numbers are assigned to different features seen under the microscope and then added up to assign the grade.

• If the numbers add up to 3-5, the cancer is grade 1 (well differentiated).
• If they add up to 6 or 7, it means the cancer is grade 2 (moderately differentiated).
• If they add up to 8 or 9 it means the cancer is grade 3 (poorly differentiated).

What does it mean if my carcinoma has tubular, mucinous, cribriform, or micropapillary features?

These are different types of ductal carcinoma which can be identified under the microscope.

Tubular, mucinous, and cribriform carcinomas are types of well-differentiated cancers that often have a better prognosis than the more common type of ductal carcinoma. Micropapillary carcinoma is a type of ductal carcinoma that often has a worse prognosis. If your doctor knows that your tumor is made up of one of these special types of breast cancer, he or she may recommend different treatment.

Since some tumors are made up of more than one type, the entire tumor must be removed (by lumpectomy or mastectomy) in order to know what types your tumor contains. A needle biopsy doesn’t give enough information to guide treatment.