Invasive lobular carcinoma (ILC) is breast cancer arising from the lobules of the mammary glands. It accounts for 5âÂÂ10% of invasive breast cancer. Rare cases of this carcinoma have been diagnosed in men (see male breast cancer).
The histologic patterns include:
Overall, the five-year survival rate of invasive lobular carcinoma was approximately 85% in 2003.
On mammography, ILC shows spiculated mass with ill-defined margins that has similar or lower density than surrounding breast tissues. This happens only at 44âÂÂ65% of the time. Architectural distortion on surrounding breast tissues is only seen in 10âÂÂ34% of the cases. It can be reported as benign in 8âÂÂ16% of the mammography cases.
Ultrasound has 68âÂÂ98% sensitivity of detecting ILC. ILC shows irregular or angular mass with hypoechoic or heterogenous internal echoes, ill-defined or spiculated margins, and posterior acoustic shadowing.
Loss of E-cadherin is common in lobular carcinoma but is also seen in other breast cancers.
Treatment includes surgery and adjuvant therapy.