Degrees of disease to b/c dx

actually, goldenlotus, I think it's more like two separate trees, the ductal tree and the lobular tree:

ADH (atypical ductal hyperplasia) -> DCIS (ductal carcinoma in situ) -> IDC (invasive ductal carcinoma)

similarly, for lobular abnormalities: ALH -> LCIS -> ILC

goldenlotus, you might want to check out other areas of breastcancer.org - there's a lot of good information here. Here's something from this site:

http://www.breastcancer.org/pictures/types/dcis/dcis_range.jsp

As Anne and leaf said, the lobular path and the ductal path are separate.  leaf explained what can happen on the lobular side of things.  On the ductal side, ADH can turn into DCIS, and DCIS can turn into IDC.  That's why a needle biopsy that shows ADH will almost always lead to an excisional biopsy, because there is a risk that some of that ADH may have already evolved to become DCIS or IDC.  The entire suspicious area is removed just to be sure that it's all ADH and nothing more. 

Importantly though, as leaf explained, most of the time that doesn't happen.  ADH is a high risk factor for breast cancer, increasing risk by "4 to 5 times higher than normal" but this increase is calculated against "base risk", which is very different than "average risk", which is what we hear about all the time.  The "average" woman has a 12.5% chance of getting breast cancer during her lifetime, but this "average" woman is a blend of all women, incorporating all risk factors.  Base risk, on the other hand, is the risk level that we all face before any of our personal risk factors are added in.  Base risk is low - it's hard to get a handle on it but I've seen numbers in the range of 4% - 6%.  So that means that only 16% - 30% of women who have ADH will end up getting breast cancer.  Whether you are on the high side or the low side of that range depends on other risk factors you may have.  Here is an explanation of this from the ACS:

"(A) recent study compared breast cancer risk between women with benign breast conditions and those without. The study found that about 5 of 100 women without any benign breast conditions developed breast cancer within the next 15 years. Among women with a benign condition that increases risk 1½ to 2 times, this would mean that about 7 to 10 out of 100 might be expected to develop breast cancer in the next 15 years. Among women with atypical hyperplasia (ductal or lobular), whose risk is 4 to 5 times normal, about 20 to 25 women out of 100 would be expected to develop breast cancer within 15 years. The risk for cancer then declines after 15 years."

http://www.cancer.org/docroot/CRI/content/CRI_2_6X_Non_Cancerous_Breast_Conditions_59.asp#How_benign_breast_conditions_affect