Breast cancer occurs when normal cells in breast tissue undergo changes that cause them grow out of control and become solid tumors. The majority of breast cancers originate from cells that line the milk ducts of the breast, but a number of other forms of breast cancers are equally serious. Learning to recognize symptoms of these cancers could be the key to early detection and treatment of a dangerous condition.
In Situ Breast Carcinoma
In situ tumors are the microscopic beginnings of a bonafide breast tumor. These small tumors are not usually apparent in a manual exam and are detected using a mammogram. According to the American Cancer Society, the majority of breast tumors originate as in situ tumors from the milk duct of the breast. These tumors are referred to as ductal carcinoma in situ, or DCIS. Other in situ tumors come from the milk-producing lobules of the breast and are referred to as lobular carcinoma in situ (LCIS). In situ breast cancer is sometimes referred to as "Stage 0" breast cancer.
Invasive Breast Cancer
As in situ tumors grow, they invade other tissues of the breast and form larger, solid tumors that are noticeable by palpitation. The American Cancer Society explains that the majority of breast tumors originate from cells of the milk duct, first as ductal carcinoma in situ, which then develops into invasive ductal carcinoma. Ductal carcinomas make up about 80 percent of all breast cancer cases. Likewise, lobular carcinoma in situ develops into invasive lobular breast cancer. Invasive lobular carcinomas are more rare, representing about 10 percent of all cases of breast cancer. Invasive breast cancer can be described as Stage I, II or III, depending on the size of the tumor and whether the tumor has spread to the lymph nodes.
Metastatic Breast Cancer
After an invasive tumor develops in the breast, it will seek its own blood supply and may become connected to the vascular and lymphatic systems. The Mayo Clinic explains that at this stage, cells from the tumor can leak or metastasize into the vasculature and invade distant tissues such as the lungs, liver and brain. Metastatic breast cancer is also referred to as Stage IV breast cancer.
Inflammatory Breast Cancer
This rare, aggressive cancer is often mistaken for an infection of the breast. According to the American Cancer Institute, this type of breast cancer makes up only 1 percent to 3 percent of breast cancer cases. Much like symptoms of breast infection, symptoms of inflammatory breast cancer include swelling of the breast, a reddening of the breast skin and the appearance of small dimples in the skin of the breast that can resemble the skin of an orange. The National Cancer Institute explains that inflammatory breast cancer is the result of tumor cells blocking the lymphatic system of the breast. Unlike more common breast cancers, however, there is typically no tumor mass in inflammatory breast cancer. Inflammatory breast cancer is not detected by mammogram and is instead diagnosed with a biopsy.
