What is invasive lobular carcinoma (ILC)?

Different kinds of breast cancer involve the lobes, lobules and/or ducts. Invasive lobular carcinoma occurs at the ends of the ducts or in the lobules. It accounts for 10% of invasive breast cancers. 
Stuart A. Linder, MD
Plastic Surgery
Infiltrating lobular carcinoma is the second most common of invasive breast cancer after infitrating ductal carcinoma. It accounts for about 7-10% of all breast cancer. It starts in the lobules and then spreads to surrounding tissue. The appearance is similar on mammogran to ductal carcinoma with a mass and spiculations. Notable difference on clinical exam includes a thickening of breast tissue rather than a hard mass. It is more often Bilateral and multicentric than infiltrating ductal carcinoma. 

Invasive lobular carcinoma (ILC) is lobular carcinoma that has spread, or invaded, the nearby tissue outside the lobes. ILC has the potential to spread, or metastasize, to other parts of the body.

ILC does not always feel like a breast lump. ILC cells may leave the lobes through one opening, staying together in a line. They can proceed to infiltrate fatty tissue, creating a web-like mass. This web of cancer cells may feel like a thickened area of breast tissue and at first may not cause concern or pain. Unfortunately, if left undetected, ILC can develop into a large mass before causing more noticeable symptoms.

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