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    Related Topics

    From Lymphatic System

    Preaortic Nodes
    Located in front of the aorta.
    Jugular Trunk
    Drains lymph from the head and neck.
    Peyer’s Patches
    Lymphoid nodules in the small intestine.
    Supraclavicular Lymph Nodes
    Located above the clavicle; key in thoracic drainage.
    Spleen
    Filters blood and initiates immune response.
    SALT
    Skin-associated lymphoid tissue.
    Lumbar Trunk
    Drains lower limbs and pelvic organs.
    Waldeyer’s Ring
    Ring of lymphoid tissue surrounding the naso- and oropharynx.
    Iliac Lymph Nodes
    Include external, internal, and common iliac nodes.
    Pharyngeal Tonsil
    Located in the nasopharynx (adenoids).
    Axillary Lymph Nodes
    Drain the upper limbs and chest wall.
    Lymph Nodes
    Small structures that filter lymph and store immune cells.
    Mastoid Lymph Nodes
    Drain the posterior scalp and ear.
    Popliteal Lymph Nodes
    Drain the foot and leg.
    Bronchomediastinal Trunk
    Drains lymph from thoracic organs.
    Red Bone Marrow
    Produces lymphocytes; site of B-cell maturation.
    Paratracheal Nodes
    Located lateral to the trachea.
    Right Lymphatic Duct
    Drains right upper quadrant of the body.
    BALT
    Bronchus-associated lymphoid tissue.
    Para-aortic Lymph Nodes
    Drain abdominal viscera and lower limbs.
    Subscapular Axillary Nodes
    Located along the posterior chest wall.
    Deep Cervical Lymph Nodes
    Located along internal jugular vein; receive lymph from head and neck.
    Superficial Cervical Lymph Nodes
    Drain superficial structures of the head and neck.
    Thymus
    Primary lymphoid organ for T-cell maturation.
    Pretracheal Nodes
    Located anterior to the trachea.

    Tracheobronchial Nodes

    Reviewed by our medical team

    Drain lungs and bronchi.

    1. Overview

    Tracheobronchial lymph nodes are a critical group of lymph nodes in the thoracic cavity located around the trachea and bronchi. They are responsible for draining lymph from the lungs, bronchi, trachea, heart, and other mediastinal structures. These nodes form a major part of the intrathoracic lymphatic drainage system and are essential in immune surveillance of the lower respiratory tract. They play a central role in pulmonary infections, immune responses, and the metastatic spread of thoracic malignancies, particularly lung cancer.

    2. Location

    Tracheobronchial nodes are located in the central thoracic region, along the trachea and main bronchi. They are anatomically divided into several key groups:

    • Paratracheal nodes: Alongside the trachea, both right and left, extending from the thoracic inlet to the carina.

    • Tracheobronchial (carinal) nodes: Located at the bifurcation of the trachea, also known as the carina.

    • Bronchopulmonary (hilar) nodes: Located at the hilum of each lung, where the main bronchi and pulmonary vessels enter and exit the lungs.

    • Interlobar and intrapulmonary nodes: Situated along the branches of the bronchi within the lungs themselves (functionally part of this group).

    These nodes are classified as stations 2 to 10 in the lung cancer lymph node staging system used in oncology (e.g., IASLC map).

    3. Structure

    Tracheobronchial nodes are encapsulated, bean-shaped lymphoid organs composed of immune cells arranged into a classic lymph node architecture:

    • Cortex: Contains lymphoid follicles rich in B lymphocytes.

    • Paracortex: Rich in T lymphocytes and dendritic cells for antigen presentation and cellular immune activation.

    • Medulla: Composed of cords and sinuses containing plasma cells and macrophages that further filter lymph and produce antibodies.

    • Capsule and trabeculae: Fibrous coverings that support and compartmentalize the node’s structure.

    Afferent lymphatic vessels bring lymph from the lungs and lower trachea into these nodes, while efferent vessels eventually drain into the bronchomediastinal lymph trunks, which then empty into the thoracic duct (left) or right lymphatic duct (right).

    4. Function

    The primary functions of the tracheobronchial nodes include:

    • Lymph filtration: Remove debris, foreign antigens, pathogens, and tumor cells from lymph draining the lungs, bronchi, and trachea.

    • Immune cell activation: Serve as a site for activation of T and B lymphocytes upon antigen detection.

    • Antibody production: Host plasma cells that secrete immunoglobulins for localized defense in the respiratory tract.

    • Coordination of mucosal immunity: Integrate signals from the respiratory mucosa to orchestrate localized and systemic immune responses.

    5. Physiological Role(s)

    Tracheobronchial nodes are central to respiratory immune surveillance and systemic lymphatic balance. Their physiological roles include:

    • First-line immune defense: Detect inhaled pathogens (e.g., viruses, bacteria, fungi) that penetrate the lower respiratory tract.

    • Immune memory generation: Aid in the formation of memory T and B cells specific to respiratory pathogens, contributing to long-term protection.

    • Lymphatic drainage regulation: Prevent pulmonary edema by returning interstitial fluid and lymph to the central circulation.

    • Tumor monitoring: Constantly survey lymph for neoplastic cells originating in the lungs and bronchi.

    6. Clinical Significance

    Lung Cancer Staging

    Tracheobronchial lymph nodes are a major component in the TNM (Tumor-Node-Metastasis) classification of lung cancer. Their involvement signifies regional spread and significantly impacts prognosis and treatment planning:

    • N1: Involvement of ipsilateral bronchopulmonary or hilar nodes.

    • N2: Involvement of ipsilateral mediastinal or subcarinal nodes (e.g., paratracheal or carinal nodes).

    • N3: Involvement of contralateral mediastinal or hilar nodes, or supraclavicular nodes.

    Respiratory Infections

    Tracheobronchial nodes become reactive and may enlarge during respiratory infections such as:

    • Pneumonia

    • Bronchitis

    • Tuberculosis (TB): Especially in primary TB, these nodes may undergo caseous necrosis and calcification (seen as Ghon complex).

    Persistent lymphadenopathy may cause compression of adjacent airways, especially in children.

    Sarcoidosis

    In sarcoidosis, non-caseating granulomas commonly involve bilateral hilar and paratracheal nodes (often termed “potato nodes” due to their size). This is one of the most common and earliest manifestations of the disease on chest imaging.

    Lymphoma and Metastatic Disease

    Lymphomas (especially Hodgkin’s lymphoma) and metastatic cancers (e.g., from breast, esophagus, or thyroid) can involve these nodes. Enlarged tracheobronchial nodes may compress the airways or blood vessels, leading to cough, dyspnea, or superior vena cava (SVC) syndrome.

    Imaging and Biopsy

    Evaluation and diagnosis involve:

    • Chest CT: Detects size, calcification, and number of lymph nodes.

    • PET-CT: Assesses metabolic activity in nodes (helpful in cancer staging).

    • Endobronchial ultrasound (EBUS): Used to guide fine needle aspiration (FNA) of paratracheal and hilar nodes.

    • Mediastinoscopy: Surgical option for biopsy when EBUS is not conclusive.

    Therapeutic Relevance

    Targeted radiotherapy or lymph node dissection during lung cancer surgery (lobectomy or pneumonectomy) often includes the tracheobronchial nodes. Their response to therapy (e.g., shrinkage) is also a key marker of treatment efficacy.

    Did you know? The spleen not only filters blood but also acts as a reservoir for blood cells, storing both red and white blood cells.