Atlas of breast cancer early detection

The margins of a mass may enable differentiation between benign and malignant. The margin is a feature that separates the mass from the adjacent breast parenchyma. Margins can be described as circumscribed or non-circumscribed.

Circumscribed margins
A circumscribed margin indicates a probable benign finding .

Non-circumscribed margins
Non-circumscribed margins are seen in lesions caused by infection, inflammation, or neoplasia. They are also seen in lesions resulting from breast trauma and surgical scarring.

Indistinct
Indistinct margins are seen in malignant masses and also in lesions caused by infection, inflammation, breast trauma, and fat necrosis. A circumscribed mass that forms after interventions such as biopsy or FNAC will often have indistinct margins .

Angular margins
Angular margins are commonly seen in malignant masses. Atypical fibroadenomas or phyllodes may also have angular margins .

Microlobulated margins
Microlobulated margins are a feature of malignancy.

Spiculated margins
Spiculated margins are seen in malignant masses. They describe the extent and possible infiltration of the mass into the surrounding breast parenchyma .