ductal carcinoma in situ

With ductal carcinoma in situ, the cells that line the breast duct become malignant, but have not yet invaded through the wall into the tissue around the duct. The cancer cells are still in place or "in situ." The risk of spread to lymph nodes or elsewhere in the body is very low if cancer is diagnosed while still in the in situ stage.

As per the NCI Carcinoma in situ is classified as either intraductal carcinoma in situ (DCIS) arising from ductal epithelium or lobular carcinoma in situ (LCIS) arising from the epithelium of the lobules. With the increasing use of screening mammography, noninvasive cancers are more frequently diagnosed and now constitute 15%-20% of all breast cancers. DCIS usually presents as microcalcifications or as a soft-tissue abnormality.There are several histologic subtypes: micropapillary, papillary, solid, cribriform, and comedocarcinoma. Some evidence suggests that comedocarcinoma may be more aggressive and associated with a higher probability of microinvasion. LCIS is usually an incidental finding when a biopsy is done for some other abnormality. Data suggest that LCIS is a risk factor for invasive cancer.