Lobular carcinoma of the breast can be divided into in situ and invasive forms. All arise from the acini or terminal ductules of lobule.
It accounts for about 10% of breast carcinomas. It tends to be multifocal - within the same breast - and bilateral in 20 %. Metastases often seed the peritoneum. In situ disease progresses to invasive carcinoma at a rate of 15% over a 20 yr period.
Last reviewed 01/2018