Sonography of Invasive Lobular Carcinoma

In patients who have known or suspected ILC, sonography has been commonly performed after mammography. Now, as more preoperative MR imaging studies are being done, sonography is often performed after MR imaging. Whether ultrasound is done after mammography, after MR imaging, or after both studies, it is important that the person performing the ultrasound study carefully review all prior imaging studies. Although meticulous attention should be paid to the region of the mammographic or the MR imaging abnormality, the remainder of the breast and the contralateral breast should be studied in a careful manner because ILC foci may be occult on mammography or MR imaging but detectable on sonography. Ultrasound along with sonographically guided biopsy can be undertaken to document the presence of ILC; to determine the extent of disease, including the presence of multifocal, multicentric, and contralateral disease; and to stage the regional lymph node basins. Sonography is an invaluable tool in the diagnosis, triage, and management of patients who have ILC.