Types of Breast Cancer

This common form of breast cancer starts in the milk ducts, which lie beneath the skin and lead to the nipple.. There are two types: Ductal carcinoma in situ (DCIS), also called intraductal carcinoma

Medullary carcinoma of the breast is a rare subtype of invasive ductal carcinoma (cancer that begins in the milk duct and spreads beyond it), accounting for about 3-5% of all cases of breast cancer. It is called “medullary” carcinoma because the tumor is a soft, fleshy mass that resembles a part of the brain called the medulla.

Mucinous carcinoma of the breast — sometimes called colloid carcinoma — is a rare form of invasive ductal carcinoma (cancer that begins in the milk duct and spreads beyond it into nearby healthy tissue).

(DCIS is a type of cancer in which the carcinoma cells are confined to the breast duct.) For information about how papillary invasive carcinoma is treated, see the section on treatment for invasive ductal carcinoma.

Tubular carcinoma of the breast is a subtype of invasive ductal carcinoma (cancer that begins inside the breast's milk duct and spreads beyond it into healthy tissue). ). Tubular carcinomas are usually small (about 1 cm or less) and made up of tube-shaped structures called "tu

Invasive ductal carcinoma (IDC), also known as infiltrating ductal carcinoma, is cancer that began growing in a milk duct and has invaded the fibrous or fatty tissue of the breast outside of the duct. IDC is the most common form of breast cancer, representing 80 percent of all breast cancer diagnoses.

Lobular breast cancer, also called invasive lobular carcinoma (ILC), occurs in the breast lobules. Lobules are the areas of the breast that produce milk. ILC is the second most common type of breast cancer.