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. An uninvolved lobule is seen on the lower left.