Proliferative lesions without atypia:

Proliferative lesions without atypia: These conditions show excessive growth of cells

in the ducts or lobules of the breast tissue. They seem to raise a woman's risk of breast
cancer slightly (1½ to 2 times normal). They include:
· Usual ductal hyperplasia (without atypia)
· Fibroadenoma
· Sclerosing adenosis
· Several papillomas (called papillomatosis)
· Radial scar
Proliferative lesions with atypia: In these conditions, there is an overgrowth of cells in
the ducts or lobules of the breast tissue, with some of the cells no longer appearing
normal. They have a stronger effect on breast cancer risk, raising it 3 1/2 to 5 times
higher than normal. These types of lesions include:
· Atypical ductal hyperplasia (ADH)
· Atypical lobular hyperplasia (ALH)
Women with a family history of breast cancer and either hyperplasia or atypical
hyperplasia have an even higher risk of developing a breast cancer.
For more information on these conditions, see our document, Non-cancerous Breast
Conditions.
Lobular carcinoma in situ
In lobular carcinoma in situ (LCIS) cells that look like cancer cells are growing in the
lobules of the milk-producing glands of the breast, but they do not grow through the wall
of the lobules. LCIS (also called lobular neoplasia) is sometimes grouped with ductal
carcinoma in situ (DCIS) as a non-invasive breast cancer, but it differs from DCIS in that
it doesn’t seem to become an invasive cancer if it isn’t treated.
Women with this condition have a 7- to 11-fold increased risk of developing invasive
cancer in either breast. For this reason, women with LCIS should make sure they have
regular mammograms and doctor visits.