| Most cancers of the breast are invasive carcinoma, | | | | benign finding called mucocele-like tumor. These |
| NST (no special type), frequently called invasive | | | | cancers are almost always estrogen and |
| ductal carcinoma, which accounts for most cancers. | | | | progesterone receptor positive and negative for |
| The remaining cancers are referred to as "special | | | | HER-2 over-expression. |
| type." The most common among the special types is | | | | - Adenoid cystic: This special type of breast cancer |
| invasive lobular carcinoma which is the second most | | | | can be found arising in other parts of the body, |
| common type after invasive carcinoma, NST. The | | | | particularly the head and neck area where they have |
| remaining invasive cancers in the special type | | | | a poor prognosis. However, in the breast, they tend |
| category are much less common and include the | | | | to behave more favorably. These cancers are almost |
| following (this list is not all-inclusive): | | | | always negative for estrogen and progesterone |
| - Invasive lobular (ILC): This type of breast cancer | | | | receptors and negative for HER-2 over-expression. |
| accounts for approximately 10-15% of all invasive | | | | - Invasive cribriform: This is another rare type of |
| carcinomas in the breast. Most of these cancers are | | | | breast cancer that can sometimes be confused with |
| Nottingham grade I or II. An exception is so-called | | | | ductal carcinoma in situ. Special studies or consultation |
| pleomorphic invasive lobular carcinoma. The cells of | | | | with a breast pathologist can help with this distinction. |
| typical ILC grow in a characteristic pattern which | | | | These cancers are usually estrogen and progesterone |
| distinguishes it from invasive carcinoma, NST. This | | | | receptor positive and negative for HER-2 |
| growth pattern often makes it difficult to determine | | | | over-expression. |
| the actual size of the cancer by clinical exam or by | | | | - Invasive papillary: This is a special type of breast |
| radiology. These cancers are almost always estrogen | | | | cancer where the cells grow in a characteristic form |
| and progesterone receptor positive and negative for | | | | similar to papillary carcinomas that can be found in |
| HER-2 over-expression. | | | | other organs, such as the ovaries and thyroid. Most |
| - Tubular: These are low grade breast cancers | | | | of these rare cancers are estrogen and progesterone |
| (Nottingham grade I) that are composed almost | | | | receptor positive and negative for HER-2 |
| entirely of invasive duct-like structures that resemble | | | | over-expression. |
| normal breast ducts. It can sometimes be difficult for | | | | - Invasive micropapillary: This rare variant of breast |
| the pathologist to distinguish this type of cancer from | | | | cancer usually has a poor prognosis. The |
| benign lesions such as sclerosing adenosis or radial | | | | characteristic appearance of the cancer is the cells |
| scar. Special studies or consultation with a breast | | | | invading the breast tissue surrounded by "clear |
| pathologist can help with this distinction. These | | | | spaces". This type of breast cancer frequently |
| cancers are almost always estrogen and | | | | spreads into the lymphatic spaces of the breast. |
| progesterone receptor positive and negative for | | | | Most of these cancers are positive for estrogen and |
| HER-2 over-expression. | | | | progesterone receptors and approximately half or |
| - Medullary: This is a rare type of breast cancer that | | | | more are positive for HER-2 over-expression. |
| has a very characteristic appearance under the | | | | - Secretory: This very rare type of breast cancer |
| microscope. These tumors are not graded using the | | | | tends to occur in younger women. These tumors |
| Nottingham system as they are a unique cancer. | | | | tend to be circumscribed and the cells have a classic |
| There are very strict criteria that a pathologist must | | | | appearance under the microscope with abundant |
| adhere to in making this particular diagnosis. These | | | | secretory material which helps distinguish this type of |
| cancers are almost always negative for estrogen and | | | | carcinoma from other types. The cancers are |
| progesterone receptors and negative for HER-2 | | | | generally negative for estrogen and progesterone |
| over-expression. | | | | receptors and negative for HER-2 over-expression. |
| - Mucinous: This is another breast cancer that has a | | | | For more information on breast cancer and breast |
| very characteristic appearance--the cancer cells | | | | pathology, visit SBPC. |
| invade the breast tissue associated with abundant | | | | © 2010 Seattle Breast Pathology Consultants, |
| mucin. They can sometimes be confused with a | | | | LLC. All rights reserved. |