Imaging of Breast Cancers With Predilection for Nonmass Pattern of Growth: Invasive Lobular Carcinoma and DCIS—Does Imaging Capture It All?

The 21-gene recurrence score in early non-ductal breast cancer: a National Cancer Database analysis

“…ILC is characterized by E-cadherin loss, and is typically hormone receptor-positive and HER2-negative 2 , 4 . Early ILC is more difficult to detect mammographically than IDC 5 , and advanced ILC is associated with a predilection for metastases to the peritoneum, gastrointestinal tract, and meninges 4 , 6 , 7 . Despite these differences, IDC and ILC are typically managed similarly.…”

Locally advanced invasive lobular carcinoma presenting as skin erythema, with multimodality imaging correlation

“…Invasive lobular carcinoma can offer considerable challenges in detection due to its pattern of proliferation. The targeted disruption of E-cadherin is inherent to ILC, which results in a dysregulation of cell adhesion and a characteristic discohesive growth pattern [ 4 , 5 ]. The tumor often grows via stromal invasion by single cells or single files of cells, resulting in minimal disruption of the normal tissue architecture [1] .…”

“…ILC tumor extent is best delineated on breast MRI [10] . Invasive lobular carcinomas tends to be larger and at later stages at the time of diagnosis, with higher rates of multifocality and bilaterality, and have unique metastatic spread patterns including gastrointestinal/genitourinary tracts, serosal surfaces, and the leptomeninges in addition to the more classic osseous, lung, and liver metastases [ 4 , 6 , 11 , 12 ].…”

“…False-negative rates for mammographic detection of ILC are estimated at 19-43%, with 35% of lesions visible on a single view [ 3 , 9 , 13 ]. Sensitivity for ILC in dense breasts is even lower, with some estimates at 8-11% [ 4 , 14 ]. Sonographic appearance of ILC can vary from hypoechoic masses to ill-defined areas of inhomogeneous echotexture or nonspecific shadowing, with estimated sensitivity for detection of 68-98% [ 4 , 15 ].…”

“…Aside from skin cancer, breast cancer is the most commonly diagnosed malignancy for women in the United States, expected in 1 of 8 women over the course of their lifetime [1] . The 2 most frequently encountered histologic subtypes of breast cancer are invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC), with the latter comprising 10-15% of invasive carcinoma cases [2] , [3] , [4] . Despite its lower incidence, the unique growth pattern of ILC can provide challenges for radiologists and pathologists in detecting this tumor as well as for surgeons when excising it.…”