Apocrine DCIS with low-grade nuclei (shown here) has to be distinguished from apocrine metaplasia. Low-grade nuclei are slightly larger and more hyperchromatic than those seen in apocrine metaplasia. Nucleoli may be punctate. Architecturally, apocrine DCIS usually shows expansive growth and complex architectural patterns seen with other forms of DCIS. Calcifications, periductal fibrosis and chronic inflammation are more common with apocrine DCIS than in benign apocrine lesions. Many neoplastic glands shown here contain intraluminal secretions.