Atlas of breast cancer early detection

Findings with unique diagnostic features on mammography include intramammary lymph node, skin lesion, and solitary dilated duct.

Intramammary lymph nodes

• Intramammary lymph nodes are seen in the vast majority of mammograms in the outer quadrant of the breast, but can occur in other parts of the breast.
• They are a common visible recognizable finding in approximately 5% of mammograms.
• They have circumscribed margins, are usually < 1 cm across, and have a lucent central hilum.
• The appearance is characteristic and does not require further investigation.
• Identifying and marking out the presence of intramammary nodes is necessary to rule out a new developing asymmetry on mammography and to avoid unnecessary biopsies.

Screening mammogram: intramammary node seen

Skin lesion
The radiologist needs to ascertain whether a lesion is intramammary or on the skin. Before the breast is positioned and the mammogram obtained, a radiopaque marker is placed on the skin lesion to confirm the mammographic location. Air trapped in the interstices distinguishes a skin lesion from an intramammary mass.

Mole on the skin

Solitary dilated duct

• A single dilated channel in the subareolar region is seen on mammography as a tubular opacity of equal density posterior to the nipple shadow in the subareolar region. If a woman presents with nipple discharge or changes in the nipple–areolar complex a detailed assessment of the dilated duct on ultrasound is performed to rule out an intraductal solid mass . Stability of the dilated duct on serial follow-up mammograms will decrease the likelihood of an intraductal mass