Since suspicious groups of microcalcifications can appear even in the absence of DCIS, a biopsy may be necessary for diagnosis. About 20–30% of those who do not receive treatment develop breast cancer. It is the most common type of pre-cancer in women. There is some disagreement on its status as a cancer; some bodies include DCIS when calculating breast cancer statistics, while others do not. Terminology
Ductal carcinoma in situ (DCIS) literally means groups of "cancerous" epithelial cells which remained in their normal location (in situ) within the ducts and lobules of the mammary gland. Clinically, it is considered a premalignant (i.e. potentially malignant) condition, because the biologically abnormal cells have not yet crossed the basement membrane to invade the surrounding tissue. When multiple lesions (known as "foci" of DCIS) are present in different quadrants of the breast, this is referred to as "multicentric" disease.For statistical purposes, some count DCIS as a "cancer", whereas others do not. When classified as a cancer, it is referred to as a non-invasive or pre-invasive form. The National Cancer Institute describes it as a "noninvasive condition". Signs and symptoms
Most of the women who develop DCIS do not experience any symptoms. The majority of cases (80-85%) are detected through screening mammography. The first signs and symptoms may appear if the cancer advances. Because of the lack of early symptoms, DCIS is most often detected at screening mammography.
Ductal carcinoma in situ (DCIS), also known as intraductal carcinoma, is a pre-cancerous or non-invasive cancerous lesion of the breast. DCIS is classified as Stage 0. It rarely produces symptoms or a breast lump one can feel, typically being detected through screening mammography. It has been diagnosed in a significant percentage of men (see male breast cancer).In DCIS, abnormal cells are found in the lining of one or more milk ducts in the breast. In situ means "in place" and refers to the fact that the abnormal cells have not moved out of the mammary duct and into any of the surrounding tissues in the breast ("pre-cancerous" refers to the fact that it has not yet become an invasive cancer). In some cases, DCIS may become invasive and spread to other tissues, but there is no way of determining which lesions will remain stable without treatment, and which will go on to become invasive. DCIS encompasses a wide spectrum of diseases ranging from low-grade lesions that are not life-threatening to high-grade (i.e. potentially highly aggressive) lesions. DCIS has been classified according to the architectural pattern of the cells (solid, cribriform, papillary, and micropapillary), tumor grade (high, intermediate, and low grade), the presence or absence of comedo histology, or the cell type forming the lesion in the case of the apocrine cell-based in situ carcinoma, apocrine ductal carcinoma in situ. DCIS can be detected on mammograms by examining tiny specks of calcium known as microcalcifications.