Benign breast disease cells. Coloured transmission electron micrograph (TEM) of the small, round, regular cells indicative of lobular carcinoma in situ (LISC). The cells are limited to the milk- producing lobes of the breast. Under a microscope, normal lobes appear empty, while abnormal lobes are crowded with cells. LISC is categorised as stage 0 breast cancer, despite not being a cancer. Instead, it is a benign breast disease that indicates an increased risk of developing breast cancer later in life. LISC is most common in pre- menopausal women. Treatment is usually non- invasive, involving regular breast examinations and mammograms.