ABBR: DCIS

A cluster of malignant cells in the mammary ducts that has not spread to surrounding breast tissue. It is the most common noninvasive breast cancer and accounts for 25% of all breast cancer diagnoses. If left untreated, as many as 50% of patients with DCIS will develop invasive cancer. Because these cells grow in the ducts, they develop without forming a palpable mass. In its early stage this condition can be diagnosed through the use of mammography.

Treatment: Lumpectomy is the most common treatment, followed by radiation. Mastectomy may be recommended if multiple areas are found or if there is a strong family history of breast cancer.

SYN: comedocarcinoma.

SEE: breast cancer; mammography.