CorpusHuman Anatomy
Lymphatic & ImmuneLymph node group

Thoracic (mediastinal and hilar) lymph nodes

Nodi lymphoidei thoracis

Also known as: mediastinal lymph nodes, hilar lymph nodes, tracheobronchial nodes, bronchopulmonary nodes, subcarinal nodes, paratracheal nodes, parasternal nodes

Parietal (parasternal, intercostal, diaphragmatic) and visceral (pulmonary, hilar, tracheobronchial, paratracheal, mediastinal) nodes that drain the thoracic wall and viscera into the bronchomediastinal trunks.

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Overview

Parietal nodes drain the thoracic wall: parasternal nodes along the internal thoracic vessels (medial breast, anterior chest and upper abdominal wall, upper surface of the liver), intercostal nodes near the heads of the ribs, and diaphragmatic nodes. Visceral nodes drain the thoracic organs: brachiocephalic (anterior mediastinal) nodes (thymus, thyroid, pericardium), posterior mediastinal nodes (oesophagus, posterior pericardium, diaphragm) and the tracheobronchial system draining the lungs.

Lung lymph flows from a superficial subpleural plexus and a deep peribronchial plexus through pulmonary (intrapulmonary) nodes along the lobar bronchi to the bronchopulmonary (hilar) nodes at the hilum, then to the inferior tracheobronchial (subcarinal) and superior tracheobronchial nodes around the carina and main bronchi, then to the paratracheal nodes, and finally into the right and left bronchomediastinal trunks. Lymph from the left lower lobe drains partly via the subcarinal nodes to the right side — relevant to staging left-sided lung cancer.

In city dwellers and smokers these nodes are often black from inhaled carbon (anthracosis) carried by alveolar macrophages.

Location

Mediastinum and lung hila; along the internal thoracic vessels and the heads of the ribs.

Parts & subdivisions

  1. Parasternal nodes
    Along the internal thoracic vessels; receive ≈ 25% of breast lymph (medial quadrants).
  2. Bronchopulmonary (hilar) nodes
    At the lung hilum; receive from intrapulmonary nodes.
  3. Inferior tracheobronchial (subcarinal) nodes
    Below the carina; enlargement may widen the carinal angle and indent the oesophagus.
  4. Superior tracheobronchial and paratracheal nodes
    Above the main bronchi and along the trachea; drain to the bronchomediastinal trunks.
  5. Brachiocephalic and posterior mediastinal nodes
    Anterior (thymus, pericardium, thyroid) and posterior (oesophagus, diaphragm) mediastinal nodes.

Anatomy

Lymphatic drainage

Into the right and left bronchomediastinal trunks → right lymphatic duct / thoracic duct (or directly into the brachiocephalic veins).

Function

  • Filter lymph from the lungs, heart, oesophagus, thymus and thoracic wall.
  • Clear inhaled particles carried by alveolar macrophages.

Clinical significance

Bilateral hilar lymphadenopathy

Classically sarcoidosis (non-caseating granulomas; often with erythema nodosum), also tuberculosis, lymphoma, silicosis ("eggshell" calcification) and metastases.

Lung-cancer nodal staging

N1 = ipsilateral peribronchial/hilar nodes; N2 = ipsilateral mediastinal and/or subcarinal; N3 = contralateral mediastinal/hilar or any scalene/supraclavicular. Sampled by endobronchial ultrasound (EBUS) or mediastinoscopy; N2–N3 disease usually precludes primary surgery.

Compiled from standard anatomy and physiology references — see the Lymphatic & Immune System sources. For education only; not medical advice.