Synopsis
Explain the non-invasive pathology and heterogeneous progression risk of ductal carcinoma in situ, then apply evidence-based breast, axillary, margin and surveillance decisions.
- DCIS consists of malignant epithelial cells confined within breast ducts by an intact basement membrane; it has no direct metastatic capacity until invasion occurs.
- Most screen-detected DCIS presents as mammographic microcalcification. Core biopsy defines grade and pattern but can underestimate invasive cancer because it samples only part of the lesion.
- Definitive management removes the involved breast area with conservation plus consideration of radiotherapy, or mastectomy when disease extent prevents acceptable conservation.
Key red flags
A palpable mass, large area of calcification, nipple change or radiology-pathology discordance with a DCIS core increases concern for occult invasion and must be addressed before choosing definitive surgery.
Investigation priorities
Characterise calcification morphology and map its full distribution before biopsy and surgery.
Management branches
A 57-year-old has a 28 mm cluster of pleomorphic calcification; stereotactic cores contain high-grade DCIS without invasion.
- Confirm specimen radiography demonstrated the target calcification and ask pathology and radiology whether the result explains the imaging appearance.
- Map the complete mammographic extent, examine the patient and identify factors increasing underestimation risk, including a mass or extensive calcification.