How is invasive lobular carcinoma (ilc) usually diagnosed?

Biopsy: The only way to definitively diagnose any cancer is by obtaining a tissue sample via a biopsy. For breast cancer this can be done as a core needle biopsy (sometimes using mammogram and ultrasound guidance), a wire needle localization biopsy, or a surgical biopsy. The pathologist then examines the biopsy tissue under a microscope and determines whether there are cancer cells present.

Biopsy: The only way to make a diagnosis of ilc is by biopsy (usually needle biopsy). The problem with ilc is that it often does not show up on a mammogram or sonogram until it is large or a lump can be felt. That is why the diagnosis of ilc is often made later than other types of breast cancer.