As we said on the first page of this pamphlet, "breast cancer" is a term for a whole family of cancers that arise in the breast. So too, is "Ductal Carcinoma in Situ" a term for a whole family of intraductal tumors. There are several different types of DCIS. The various types are descriptions of how the DCIS tumors look under the microscope. There is a division of the various types into two groups, the non-comedo types and comedo type carcinoma in situ:
Solid type, Ductal Carcinoma in Situ: The tumor cellscompletely fill the involved ducts.
Cribiform type, Ductal Carcinoma in Situ: The tumor cells do not completely fill the ducts. The pattern has little holes and slits, similar to a sieve.
Papillary and micropapillary types, Ductal Carcinoma in Situ:
These two types have fern-like projections of cells into the center of the duct. The micropapillary type projections are smaller than those seen with the papillary type.
Comedo type Ductal Carcinoma in Situ, also called Comedocarcinoma: Comedo type DCIS is separated out from the other types of DCIS, not only by how it looks under the microscope, but also how it acts. Comedocarci- noma tends to be slightly more aggressive than the other forms of DCIS. The little individual cells that make up this tumor are more aggressive in how they look under the microscope, and in how they act biologically. As a matter of fact, these cells are closer to real invasive breast cancer cells in how they look and behave than any other form of DCIS.
The appearance of Comedocarcinoma under the microscope is very distinct from the other forms of DCIS. The individual cells look more abnormal, and the center of the duct is plugged up with dead cellular debris. This dead cancer cell debris is known as necrosis. Necrosis in cancer growths seen under the microscope usually means that the cancer is growing fast, and generally is more aggressive in how it behaves. Also seen very often in the areas of necrosis are microcalcifications, small abnormal calcium deposits ( these microcalcifications are seen on mammograms).