Infiltrating lobular carcinoma (5 to 10 percent of breast cancers), which is often detected as a thickening of the breast tissue rather than as a lump, may be found in many places, not only in the same breast but also in the opposite one.
Other infiltrating cancers include Paget's disease, a cancer that begins in the area of the nipple and is associated with bleeding, redness, itching and burning (this is not the same as Paget's disease of bone, which is a chronic benign process), and inflammatory breast cancer, which shows up as a hot, red, swollen area having the appearance of an infection or inflammation . This sub-type has a worse prognosis , because the red color and warmth of the skin indicate that tumor cells have already spread into many lymphatic vessels.
In situ cancers are confined within the lining of the ducts or lobules. These are early cancers or precancerous lesions that have not developed the ability to become invasive. They are generally of two types. Ductal in situ carcinomas (also called intraductal or ductal carcinoma in situ [DCIS]) do have the ability over a long period to become invasive cancer if untreated. So these tumors have to be completely removed. In situ lobular cancers (also called lobular carcinoma in situ [LCIS) are best understood as markers for the risk of developing cancer. It is not usually possible to remove all lobular carcinomas in situ without removing all of both breasts. This is excessive treatment in most situations, so very careful follow-up is often recommended after removal of the in situ lesion. Treatment at the time of diagnosis may also include radiotherapy (for DCIS only).
Nearly all breast cancers arise from glandular tissue (adenocarcinomas), although other types also occur, including squamous cell carcinomas, sarcomas, carcinosarcomas, cystosarcoma phylloides and sweat gland
