Lobular carcinoma in situ is rare mainly because lobular carcinoma in situ may progress into invasive carcinoma, and many patients have already entered the stage of invasive carcinoma when they are found, which does not belong to rare disease, but just that they have already entered the stage of invasive carcinoma when they are found. Lobular carcinoma in situ means that the tumor cells are still confined to the lobules of the breast, without breaking through the end of the lobules or the ducts, including the basement membrane of some glandular follicles. Lobular carcinoma in situ of the breast is a noninvasive lesion originating in the terminal ducts and lobules, and is therefore generally precancerous. It is not a rare disease, mainly because lobular carcinoma in situ may progress to invasive carcinoma, and many patients are found to be in the invasive stage by the time it is detected If you feel uncomfortable symptoms, you should consult a doctor in time to identify the cause of the disease and then treat it.