Browse the corpus

The axilla is a small anatomical space located between the upper thoracic wall and the arm. The main contents include the brachial plexus, axillary artery and vein, and axillary lymph nodes.[1] Lymph nodes contain a range of immune cells, including lymphocytes and macrophages. These remove damaged cells, foreign material, and microorganisms from the lymphatic fluid before returning it to the venous circulation.[2] The axillary lymph nodes arrange into five groups based on their anatomical relations. Collectively, they drain the wall of the thorax, breast, arm, and upper abdominal wall above the umbilicus. The axillary lymph nodes are of particular clinical significance as they are often the first site of breast cancer metastasis.[3] Axillary node involvement is the single most significant prognostic variable for breast cancer patients.[4] Axillary lymphadenopathy is also associated with hematological malignancies, infection, and various autoimmune etiologies.[5] It is, therefore, crucial to have a thorough understanding of this region. In this article, we will focus primarily on the axillary lymph nodes respective to their anatomical features, relations, drainage, surgical considerations, and clinical significance.