axillary lymph node
Meaning of axillary lymph node: Axillary lymph nodes filter lymph draining from the arm, chest wall, and breast, and are checked in infection, injury, and cancer staging.
Definition of axillary lymph node
An axillary lymph node is a small, bean-shaped structure located in the axilla, commonly known as the armpit, that forms part of the lymphatic system. These nodes filter lymph fluid draining from the arm, the chest wall, and the breast, trapping bacteria, viruses, and abnormal cells while housing immune cells that help mount a response against them.
Axillary lymph nodes can become enlarged or tender for many reasons, including a local infection or injury involving the arm or chest wall, and this kind of enlargement is generally temporary and resolves as the underlying cause improves. Axillary lymph nodes are also closely examined in breast cancer, since breast cancer cells commonly spread first to these nearby nodes before reaching more distant sites.
Because the axillary nodes serve as a common early site of spread from a breast tumor, their examination, whether by physical exam, imaging, or biopsy, plays a central role in determining how advanced a breast cancer is.
Used in a sentence
Imaging identified enlarged axillary lymph nodes during staging of the patient's newly diagnosed breast cancer.
Good to know
Axillary lymph node enlargement is often caused by ordinary infection or injury rather than cancer, though in the context of a known or suspected breast tumor, these same nodes are evaluated specifically for possible spread of disease.
Word origin
Where “axillary lymph node” comes from
Axillary is formed from Latin axilla, meaning armpit; lymph derives from Latin lympha, meaning clear water, an early description of the fluid these nodes filter.