invasive lobular carcinoma invasive lobular carcinoma invasive lobular carcinoma (ilc) is breast cancer arising from the lobules of the mammary glands. it accounts for 5–10% of invasive breast cancer. rare cases of this carcinoma have been diagnosed in men (see male breast cancer). invasive lobular carcinomalobules of the mammary glands.specialtyoncology histopathologic types of breast cancer, with relative incidences and prognoses, with "invasive lobular carcinoma" at top right types most common features classic lobular pleomorphic lobular gradeslow or high (ii/iii)high (iii) ajcc stageiii lymph node statusnegativepositive er/pr statuspositivepositive surgery typelumpectomymastectomy the histologic patterns include: type prevalence description image classical 40% round or ovoid cells with little cytoplasm in a single-file infiltrating pattern, sometimes concentrically giving a targetoid pattern mixed 40% no dominant pattern solid 10% sheets of classical-appearing cells with little intervening stroma alveolar 5% aggregates of classical-appearing cells tubulolobular 5% cells form microtubules in >90% of tumor (smaller than in tubular carcinoma) pleomorphic classical-appearing but with pleomorphic cells. it may include signet-ring cells, or plasmacytoid cells (pictured) which have abundant cytoplasm and eccentric nuclei. histopathology of invasive lobular carcinoma (ilc), next to lobular carcinoma in situ (lcis) invasive lobular carcinoma demonstrating a predominantly lobular growth pattern lobular breast cancer. single file cells and cell nests. prognosis overall, the five-year survival rate of invasive lobular carcinoma was approximately 85% in 2003. diagnosis on mammography, ilc shows spiculated mass with ill-defined margins that has similar or lower density than surrounding breast tissues. this happens only at 44–65% of the time. architectural distortion on surrounding breast tissues is only seen in 10–34% of the cases. it can be reported as benign in 8–16% of the mammography cases. ultrasound has 68–98% sensitivity of detecting ilc. ilc shows irregular or angular mass with hypoechoic or heterogenous internal echoes, ill-defined or spiculated margins, and posterior acoustic shadowin. loss of e-cadherin is common in lobular carcinoma but is also seen in other breast cancers. treatment treatment includes surgery and adjuvant therapy.