Significant Nodal Groups
A. Internal jugular chain (deep cervical).
B. Spinal accessory chain (posterior triangle).
C. Transverse cervical (supraclavicular).
The highest jugular digastric node near the angle of the mandible is called the "sentinel" node.
The "signal" node is the lowest along the internal jugular chain called the virchow nodes.
If only a virchow node is present, then one should check the abdomen and/or chest for primary source of metastasis.
The internal jugular chain is divided into:
High: Above the hyoid.
Mid: Between hyoid and cricoid.
Low: Below the cricoid.
The internal jugular chain is a common final pathway that receives drainages from parotid, retropharyngeal, and submandibular/submental groups. Drainage from the internal jugular chain is into the subclavian vein and/or internal jugular vein and/or into the right lymphatic duct and thoracic duct.
Spinal accessory (posterior triangle) nodal group receives occipital/mastoid, lateral neck, scalp, nasal pharyngeal sources.
Abnormal spinal accessory nodes may indicate the presence of an early nasal pharyngeal cancer.
Transverse cervical chain receives drainage from deep cervical, supraclavicular, subclavicular, upper chest, anterior lateral neck. Sources. The drainage is the same as for the internal jugular chain.
Submental nodes receive drainage from adjacent skin, lips, floor of the mouth, and drain to the submandibular nodal group.
Submandibular nodes are extra glandular and receive drainage from anterior face, flow of the mouth, anterior oral cavity, and submental nodal group. Drainage is to the high internal jugular chain.
Parotid Nodal Group
Intra or extra glandular nodes.
Receives drainage from external artery canal, eustachian tube, adjacent skin, buccal mucosa. (skin squamous cell cancer and melanoma frequently metastasize to this group). Drainage is to high internal jugular chain.
Retropharyngeal Nodal Group
Two compartments: Medial and lateral retropharyngeal.
Medial retropharyngeal receives drainage from nasal pharynx and oral pharynx and drains to high internal jugular chain.
Lateral retropharyngeal (nodes of Rouvierre) are located just medial to the internal carotid artery. Drainage is the same as for the medial retropharyngeal nodes.
Early sign of nasal pharyngeal cancer may be presence of abnormal lateral retropharyngeal node in the patient over forty.
Anterior Cervical Nodal Group
Anterior jugular: superficial. Follows the course of the external jugular vein. Receives drainage from skin and muscles of the anterior neck. Drains to the thoracic duct.
Paraesophageal group: Tracheal esophageal groove nodes and delphian node. Abnormal delphian node is often an indicator subglottic laryngeal cancer extension.
This group receives drainages from hypopharynx, larynx, thyroid, and esophagus. Drainage is then to the thoracic duct.
Simplified Nodal Classification
Is associated with a fifty percent reduction in long term survival.
Abnormal (malignant) Nodes
Staging information is necessary for selection for most appropriate treatment option.
Ten to thirty percent of malignant nodes are clinically undetected on physical examination due to deep location especially in retropharyngeal and high internal jugular chains.
Accuracy of nodal staging CT: Ninety to ninety-five percent. Physical exam seventy-five percent.
Pitfalls of physical exam:
Nodal conglomerates may be mistaken for a single node.
Can't determine extracapsular spread.
Difficult to detect deep nodes.
Clinical Nodal Staging
Modified AJCC (Harnsberger) Nodal Staging
Extracapsular spread carries a grave prognosis and may be the best indicator of treatment failure.
Signs of Extracapsular Spread
Encasement of vessels.
Accuracy Comparison CT versus MR:
CT = MR for detecting and sizing nodes.
CT better than MR for demonstrating necrosis.
CT better than MR for detecting extracapsular spread.
Nodes from Unknown Primary
Probable Source of Nodal Metastasis
Usually non-Hodgkin's lymphoma: Large nodes, enlargement of Waldeyer's ring, extra lymphatic enlargement of particular glands such as the thyroid.
Hodgkin's lymphoma may be present (25 percent of head & neck lymphoma) particularly if there is also a mediastinal involvement.
Lymphomas can cross fascial planes easily.
Can undergo rapid enlargement.
Differential diagnosis: squamous cell cancer, infectious mononucleosis.
Inflammatory disease leading to pseudo necrosis with TB or abnormal enlargement with cat scratch, sarcoid.
Post inflammatory fatty infiltration: (These nodes will be oval and low density of fat should not be central).
Painless posterior neck mass.
Scrofula: Common in Southeast Asia, (California).
Necrotic nodes particularly in level 5.
Multi-loculated disturbed fat planes, thick rim enhancement.
May calcify following treatment.
Abnormal nodes in chest and head and neck.
Usually non-necrotic but brightly enhanced with contrast.
Multiple large non-necrotic nodes.
Enlargement of Waldeyer's ring.
Appears similar to AIDS, sarcoid, leukemia, lymphoma.
Cat Scratch Fever
Bilateral large nodes including intraparotid nodes.
Uncertain etiology ? viral or ricketsial.
Multiple small nodes.
Enlargement of Waldeyer's ring.
Associated lympho epithelial cyst.
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