Among the following statements, true about DCIS breast is:

Ductal Carcinoma in Situ (DCIS) DCIS is a malignant clonal proliferation of epithelial cells limited to ducts and lobules by the basement membrane DCIS can spread throughout the ductal system and produce extensive lesions involving an entire sector of a breast. DCIS is almost always detected by mammography. Histologically:-DCIS can be divided into two major architectural subtypes: Comedo It is defined by two features: Tumor cells with pleomorphic, highgrade nuclei and Areas of central necrosis Noncomedo Lacks either high-grade nuclei or central necrosis Calcifications may also be seen in noncomedo forms of DCIS in association with focal necrosis or intraluminal secretions.