Here is a description of the diagnostic stages of breast cancer:
Early stage or stage 0 breast cancer: The disease is localized within the breast and has not invaded surrounding breast tissue, and there is no evidence of spread to the lymph nodes (carcinoma in situ).
Stage 1 breast cancer: The cancer is two centimeters or less in size. It may have spread microscopically to lymph nodes in the underarm.
Stage 2A breast cancer: A tumor is less than two centimeters across with lymph node involvement that is greater than 2 mm in the underarm and/or has spread to lymph nodes underneath the chest wall, OR the tumor is larger than 2 cm (but less than five) across without underarm lymph node involvement.
Stage 2B breast cancer: A tumor is greater than 5 cm across without lymph node or chest wall involvement, or the tumor is larger than 2 cm but less than 5 cm across with lymph node involvement.
Stage 3A breast cancer, also called locally advanced breast cancer: The tumor is larger than 5 cm and has spread to the lymph nodes under the arm, or a tumor is less than 5 cm with involvement of 4-9 axillary lymph nodes.
Stage 3B breast cancer: A tumor of any size has spread to the skin, chest wall, or internal mammary lymph nodes (located beneath the breast and inside the chest). Inflammatory breast cancer falls into this category.
Stage 3C breast cancer: A tumor of any size has spread to more than 10 axillary lymph nodes or to lymph nodes near the collar bone.
Stage 4 breast cancer: A tumor, regardless of size, has spread to places far away from the breast, such as bones, lungs, liver, brain, or distant lymph nodes.
Most breast tumors in children are fibroadenomas, which are benign (not cancer). Rarely, these tumors become large phyllodes tumors (cancer) and begin to grow quickly. If a benign tumor begins to grow quickly, a fine-needle aspiration (FNA) biopsy or an excisional biopsy will be done. The tissues removed during the biopsy will be viewed under a microscope by a pathologist to check for signs of cancer.
Breast cancer is a disease in which malignant (cancer) cells form...