NCCN Guidelines for Patients
Breast Cancer - Carcinoma in Situ
, Version 1.2016
Carcinoma in situ
The 3 types
The 3 types
Carcinoma in situ is a confusing term. “Carcinoma”
is a type of cancer that starts in cells that make up
the skin or tissue that lines or covers organs. “In situ”
means that no abnormal cells have grown into the
stroma. However, not all carcinoma in situ is cancer.
Lobular carcinoma in situ
Although called a carcinoma, LCIS (
itu) isn’t cancer. It is an abnormal cell
growth within the lobules. However, having had LCIS
increases your chances for breast cancer.
Ductal carcinoma in situ
itu) is breast cancer. It
is a carcinoma that started in ductal cells and hasn’t
grown outside the breast ducts. If left untreated, DCIS
could grow outside of the ducts and spread beyond
Paget's disease of the breast
Paget's disease of the breast is breast cancer. It is a
carcinoma involving the nipple. It is a very rare form
of breast cancer and isn't addressed in this book.
Figure 1.1 Inside women’s breasts
Inside of women’s breasts are millions of lobules that form breast milk after a baby is born.
Breast milk drains from the lobules into ducts that carry the milk to the nipple. Around the
lobules and ducts is soft tissue called stroma.
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