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    Related Topics

    From Lymphatic System

    Lymph Nodes
    Small structures that filter lymph and store immune cells.
    Para-aortic Lymph Nodes
    Drain abdominal viscera and lower limbs.
    Tracheobronchial Nodes
    Drain lungs and bronchi.
    Occipital Lymph Nodes
    Drain the back of the scalp.
    Pretracheal Nodes
    Located anterior to the trachea.
    Thoracic Duct
    Main lymphatic duct draining most of the body.
    Subscapular Axillary Nodes
    Located along the posterior chest wall.
    Inguinal Lymph Nodes
    Drain the lower limbs and external genitalia.
    Lymphatic Capillaries
    Initial lymphatic vessels that collect interstitial fluid.
    Pharyngeal Tonsil
    Located in the nasopharynx (adenoids).
    Preaortic Nodes
    Located in front of the aorta.
    MALT
    Mucosa-associated lymphoid tissue.
    Mesenteric Lymph Nodes
    Drain the intestines and abdominal structures.
    Posterior Mediastinal Nodes
    Drain posterior thoracic structures.
    Anterior Mediastinal Nodes
    Drain anterior thoracic structures.
    Cisterna Chyli
    Dilated sac at the start of the thoracic duct.
    Deep Cervical Lymph Nodes
    Located along internal jugular vein; receive lymph from head and neck.
    Waldeyer’s Ring
    Ring of lymphoid tissue surrounding the naso- and oropharynx.
    Popliteal Lymph Nodes
    Drain the foot and leg.
    NALT
    Nasal-associated lymphoid tissue.
    Pectoral Axillary Nodes
    Located along the anterior chest wall.
    Parotid Lymph Nodes
    Drain the lateral face and scalp.
    Palatine Tonsils
    Located on each side of the oropharynx.
    Paratracheal Nodes
    Located lateral to the trachea.
    Appendix
    Lymphoid-rich structure of the large intestine.

    Apical Axillary Nodes

    Reviewed by our medical team

    Located at the apex of the axilla.

    1. Overview

    The apical axillary lymph nodes, also known as subclavicular or medial axillary nodes, are the highest group of lymph nodes in the axilla (armpit region). As the final relay point in the axillary lymphatic chain, they receive lymph from all other axillary lymph node groups as well as directly from some upper limb and thoracic regions. These nodes are critical for filtering lymph before it enters the subclavian lymphatic trunk and ultimately drains into the central venous system. Clinically, the apical axillary nodes are highly significant, especially in the context of breast cancer and upper limb infections.

    2. Location

    The apical axillary nodes are located in the apex of the axilla, near the lateral border of the first rib. Their anatomical relationships include:

    • Superior to: The central and other axillary node groups (anterior/pectoral, posterior/subscapular, and lateral/humeral).

    • Medial to: The axillary vein.

    • Posterior to: The clavicle.

    They lie deep to the clavipectoral fascia and are often found clustered around the axillary vein and the beginning of the subclavian vessels. Efferent vessels from these nodes contribute to the formation of the subclavian lymph trunk.

    3. Structure

    Like other lymph nodes, the apical axillary nodes are bean-shaped, encapsulated lymphoid organs composed of organized immune tissue. They contain:

    • Cortex: Contains lymphoid follicles rich in B lymphocytes.

    • Paracortex: T cell zone that houses dendritic cells for antigen presentation and T cell activation.

    • Medulla: Contains medullary cords and sinuses with macrophages, plasma cells, and reticular cells.

    They receive lymph via afferent vessels from central and other axillary groups, as well as directly from lymphatic vessels draining the upper limb and thoracic wall. Efferent vessels from these nodes ascend and converge into the subclavian trunk, which drains into either the thoracic duct (on the left) or right lymphatic duct (on the right).

    4. Function

    The apical axillary nodes serve as the final filtration and immunological checkpoint in the axillary lymphatic chain. Their key functions include:

    • Lymph filtration: Remove debris, pathogens, and cancer cells from lymph received from other axillary nodes and direct tributaries.

    • Immune response coordination: Host B and T cells that initiate adaptive immune responses when antigens are encountered.

    • Drainage of lymph to central circulation: Act as the main conduit for transferring filtered lymph into the subclavian lymph trunk and then into the venous system.

    5. Physiological Role(s)

    The apical axillary nodes contribute to overall immune surveillance and lymphatic drainage in the upper body. Their physiological roles include:

    • Maintaining fluid balance: By returning filtered interstitial fluid from the upper limb, breast, and upper thorax to the bloodstream.

    • Protection against infection: Filter lymph to detect and respond to pathogens, especially from the skin and soft tissue of the arm and upper chest.

    • Immune regulation: Facilitate the development of adaptive immune responses through antigen presentation and lymphocyte activation.

    • Inflammatory response: Participate in inflammatory signaling and cellular recruitment during localized or systemic immune challenges.

    6. Clinical Significance

    Breast Cancer Staging

    The apical axillary lymph nodes are of particular importance in the staging and management of breast cancer. They are classified as Level III axillary nodes (above the pectoralis minor muscle), and involvement of these nodes often indicates advanced disease. Key points:

    • Sentinel lymph node biopsy: Though usually sampled from lower axillary levels, spread to apical nodes can alter surgical and oncologic decisions.

    • Axillary lymph node dissection (ALND): Involves removal of apical nodes in certain cancer surgeries.

    Upper Limb and Chest Wall Infections

    Infections such as cellulitis of the upper limb or thoracic wall may lead to reactive enlargement and tenderness of the apical axillary nodes. These nodes are examined during physical evaluation for signs of systemic or localized infection.

    Lymphadenopathy

    Enlargement of apical nodes may result from:

    • Infections: Such as tuberculosis or cat-scratch disease.

    • Malignancies: Including breast carcinoma, melanoma, or lymphomas.

    • Autoimmune diseases: Like rheumatoid arthritis or lupus, leading to generalized lymph node enlargement.

    Surgical Risk

    During axillary surgeries, especially mastectomy or lymph node dissections, care must be taken to avoid injury to surrounding structures such as the subclavian vein and brachial plexus when removing apical nodes. Damage can result in complications like lymphedema, nerve injury, or vascular compromise.

    Imaging and Evaluation

    Apical axillary nodes are not easily palpable due to their deep location. Diagnostic modalities include:

    • Ultrasound: First-line for evaluating axillary lymphadenopathy.

    • MRI and CT: Used to assess deeper node involvement, particularly in cancer staging.

    • Fine needle aspiration (FNA) or core biopsy: May be used for cytological or histological diagnosis.

    Did you know? The lymphatic system plays a crucial role in immune defense by transporting white blood cells to lymph nodes and other tissues.