Lobular carcinoma-in-situ (LCIS) is a non-palpable lesion which is usually an incidental finding in breasts removed for other reasons. It is multicentric in 70% of cases and bilateral in 30% to 40% of cases. The lobules are distended with uniform round or oval, medium sized cells. The nuclei are uniform and normochromatic. This image shows LCIS involving several lobules. A few uninvolved lobules can be seen on the right.