Ductal carcinoma in situ

What it is

Ductal carcinoma in situ is the non-invasive form of ductal breast cancer, the ductal group making up 85-90% of breast cancer. What is described are the forms the malignant cells take inside the duct:

• Solid: ducts filled with malignant cells.
• Comedo: with central necrosis, and common.
• Cribriform appearance.
• Papillary projections, and common.
• Clinging: cells clinging to the duct wall.

In the TNM staging, Tis is carcinoma in situ or Paget's.

Lobular carcinoma in situ is the contrast worth holding beside it. It is nil on mammogram, rarely expresses the C-erb 2 oncogene, carries a 15% risk at 20 years of developing breast cancer and a greater frequency of bilateral disease, and is treated as a risk marker for that raised bilateral risk.

How it is diagnosed

Triple assessment applies as it does to any breast mass: history and clinical examination, imaging, then histopathology or cytology. Two points bear on in situ disease.

FNAC cannot differentiate in situ from invasive. The tru-cut or core biopsy is therefore what settles the question, and it is mandatory before starting any type of treatment.

On imaging the feature given for ductal carcinoma in situ is microcalcifications.