Invasive lobular carcinoma, also called infiltrating lobular carcinoma, is less common than invasive ductal carcinoma. It accounts for about 10% of all invasive breast cancers.
Invasive lobular carcinoma starts in the lobules of the breast, but grows through the lobules and spreads into nearby breast tissue. It can also spread (metastasize) to the lymph nodes and other parts of the body.
Lobular carcinoma can occur in several areas in one breast (called multi-focal or multi-centric) or in both breasts. Lobular carcinoma is more likely to occur in both breasts than other types of breast cancer.
Rather than forming a lump, lobular carcinoma grows in a single strand into the fatty tissues of the breast, creating a thickened area of breast tissue. There may be skin changes on the breast, such as a different texture or dimpling.
It is difficult to diagnose invasive lobular carcinoma by mammography. Ultrasound or magnetic resonance imaging (MRI) may be used to find lobular carcinoma, but biopsybiopsyThe removal of cells or tissues for examination under a microscope. is the most common diagnostic test for lobular carcinoma.