Synopsis
Recognise accessory breast and nipple tissue along the embryological milk line, distinguish it from nodal and skin masses, and investigate new focal change using the same diagnostic standards as pectoral breast tissue.
- Accessory breast tissue results from incomplete regression of the embryological mammary ridge and occurs most often in the axilla, with or without an accessory nipple.
- Hormonal responsiveness can cause cyclical tenderness, pregnancy-related enlargement or milk secretion, which often makes previously unnoticed tissue symptomatic.
- Examination should decide whether an axillary fullness is glandular tissue, a lymph node, lipoma, epidermal cyst, hidradenitis or another soft-tissue mass.
Investigation priorities
Localise the structure and distinguish glandular tissue from node, cyst, lipoma or abscess.
Management branches
During late pregnancy, a patient develops bilateral soft axillary fullness that is tender and enlarges with breast engorgement.
- Examine both axillae and breasts, documenting whether tissue is diffuse and symmetrical and checking for a dominant mass, infection, skin lesion or abnormal node.
- Use ultrasound if anatomy is uncertain or any focal feature exists; avoid assuming every pregnancy-related axillary swelling is a node or abscess.
Stable benign accessory tissue repeatedly chafes, restricts arm movement and causes substantial distress despite conservative measures.