Ductal Carcinoma in Situ of the Breast

Variant: Apocrine Ductal Carcinoma In Situ

Abundant eosinophilic apocrine cytoplasm
Same criteria as usual DCIS except that usual nuclear size criteria cannot be used as nuclei in apocrine metaplasia are typically large
Special nuclear size criteria based on comparison to benign apocrine metaplastic cells
- Low and intermediate grades: up to 4x size of benign apocrine nuclei, at most slight pleomorphism
- High grade: at least 5x size of benign apocrine nuclei, pleomorphism
  - Necrosis is almost always present
Low grade apocrine DCIS must also have architectural features of usual low grade DCIS
- May be less well developed
No known significance for apocrine DCIS beyond that for usual DCIS