Women are born with a small number of Type 1
breast lobules, which are units of milk glands and duct cells.
Pathologically, inflammation affecting
breast lobules or lobulitis and the formation of non-caseating granulomas composed of clustered epitheloid histiocytes is present.
In granulomatous mastitis, granulomas are usually non-necrotizing, inflammation is focused around
breast lobules that clinically may present as a painless mass (15).
Sections of the breast mass biopsy revealed high-grade adenocarcinoma (Figure 9, A through C) and a small focus of residual benign
breast lobules (lower, right section of Figure 9, A and B).
On the one hand, aborting a pregnancy increases the likelihood of breast cancer because it short-circuits the natural maturation process by which cancer-vulnerable
breast lobules (which increase massively during pregnancy) are replaced by cancer-resistant
breast lobules.
During the "susceptibility window," nearly all of the
breast lobules consist of cancer-susceptible Type 1 and 2 lobules, where 95% of all breast cancers originate.
An autoimmune reaction against secretions that leak to the interstitium from
breast lobules is the suspected mechanism of the disease.