2. CONTENTS
†Lymphatic drainage of the head and neck
† Levels of lymph nodes
† Anatomy and clinical importance of lymph nodes
† Occult primary
† Neck dissection
‡ Types
‡ Indications and contraindications
‡ AJCC Staging
‡ Complications
‡ Incisions
‡ Reconstruction techniques
3. LYMPHATIC DRAINAGE OF THE HEAD AND NECK
Out of total 800 lymph nodes in the body, about 300 lymph nodes are located in the head and neck region.
-The knowledge of lymphatic drainage of the head and
neck is important because the cancers arising in
this region have predictable patterns of spread through
the chains of lymph nodes, which can help the surgeons to
remove the desired lymph nodes.
-The lymph nodes and other lymphoid tissues in the head
and neck are often inflamed and produce swellings, which
can be clinically palpated.
-All the lymph from the region of head and neck drains into
DEEP CERVICAL LYMPH NODES either (a) directly from the
tissues or (b) indirectly after passing through the outlying
groups of lymph nodes.
These are broadly classified into two groups:
(1)Peripheral
(2)Terminal
4. PERIPHERAL LYMPH NODES
Peripheral lymph nodes (also called outlying lymph nodes) are usually found in groups, which are arranged in
outer and inner circles.
1. Outer circle: It is formed by lymph node groups, which form the peri-cervical or cervical collar at the
junction of the head and neck (cranio-cervical junction) and extends from chin in front to the occiput behind.
-They include submental, submandibular, superficial parotid (preauricular), mastoid (postauricular), and
occipital nodes.
2. Inner circle: The inner circle of lymph nodes lie deep to the investing layer of deep cervical fascia.
5. TERMINAL LYMPH NODES
These are deep cervical lymph nodes that lie along and around
the internal jugular vein, some within and some on the surface of
the carotid sheath, under cover of the sternocleidomastoid muscle.
For the convenience of description the deep cervical lymph nodes
are divided into upper (superior) and lower(inferior) groups,
though there is no clear demarcation between them.
1. Superior group of deep cervical lymph nodes: They lie above
the omohyoid. One lymph node of this group is situated below
the posterior belly of digastric between the angle of the
mandible and anterior border of the sternocleidomastoid in the
triangle formed by posterior belly of digastric, facial vein, and
internal jugular vein. It is called jugulodigastric node. It drains
the lymph primarily from the palatine tonsil. Therefore it is also
termed lymph node of the tonsil. When enlarged due to
pathology in the palatine tonsil, it is easily palpable behind and
below the angle of the mandible.
2. Lower group of deep cervical lymph nodes: One of the lymph
nodes of this group lies above the intermediate tendon of
omohyoid posterior to the internal jugular vein. It is called jugulo-
omohyoid lymph node. Since this lymph node drains lymph
primarily from the tongue, it is termed lymph node of the tongue.
This node lies deep to sternocleidomastoid, and therefore, can be
palpated only if enlarged considerably.
6. PERIPHERAL LYMPH NODES
Submental (tip of the tongue, floor of the mouth, lower lip and chin)
Submandibular (scalp, face and tongue)
Parotid (anterior scalp, external and middle ear and parotid gland)
Mastoid (posterior scalp, pinna and external auditory canal)
Suboccipital (back of scalp and neck)
TERMINAL LYMPH NODES
Tracheal (trachea, larynx, thyroid, and superficial neck, below hyoid)
Retropharyngeal (nasopharynx, eustachian tube and middle ear)
Superficial cervical (along the EJV and drains the lower parotid, pinna, mastoid and angle of mandible)
Deep cervical (along the IJV and gets lymph from entire head and neck, either directly or through regional LN)
-Superior group with jugulo-digastric node (palatine tonsil and posterior 1/3 of the tongue, larynx, pharynx)
-Inferior group with jugulo-omohyoid node (ant 2/3 of tongue, larynx, thyroid gland)
8. LEVEL 1A(SUBMENTAL)-
Superiorly -Symphysis of mandible
Inferiorly- Body of hyoid
Laterally- Anterior belly of ipsilateral digastric muscle
Medially -Anterior belly of contralateral digastric muscle
They lie on the mylohyoid muscle in the submental triangle, 2-8 in number.
-Afferents come from the chin, middle part of lower lip, anterior gums, anterior floor of
mouth and tip of tongue.
-Efferent goes to submandibular nodes and internal jugular chain.
LEVEL 1B(SUBMANDIBULAR)-
Anteriorly- Anterior belly of digastric muscle
Superiorly -Body of mandible
Inferiorly -Inferior edge of hyoid bone
Posteriorly(Lateral) -Vertical plane defined by posterior border of submandibular gland
Medially- anterior belly of digastric muscle.
-They lie in submandibular triangle in relation to submandibular gland and facial artery.
-Afferents come from lateral part of the lower lip, upper lip, cheek, nasal vestibule, gums, teeth,
medial canthus, soft palate, anterior pillar, anterior part of tongue, submandibular and
sublingual salivary glands and floor of mouth.
-Efferents go to internal jugular chain.
9. LEVEL-2A (UPPER JUGULAR)-
Superiorly- Skull base
Inferiorly- inferior border of hyoid bone, carotid bifurcation.
Laterally (posterior) -posterior border if internal jugular vein, vertical plane
defined by spinal accessory nerve.
Medially -Anterior edge of sternocleidomastoid muscle, posterior edge of
submandibular gland.
LEVEL-2B (SUBMUSCULAR RECESS)-
Superiorly- Skull base.
Inferiorly- horizontal plane defined by Inferior border of hyoid bone,
carotid bifurcation.
Laterally (Posterior)- Lateral border of sternocleidomastoid muscle.
10. LEVEL 3 (MID JUGULAR)-
Superiorly-horizontal plane defined by Inferior border of hyoid bone
Inferiorly-horizontal plane defined by Inferior border of cricoid cartilage,
Omohyoid muscle.
Laterally(Posterior)-Lateral border of sternocleidomastoid muscle,
sensory branches of cervical plexus.
Medially-Medial border of SCM muscle, Medial aspect of common carotid artery,
Scalenus muscle, Sternohyoid muscle.
LEVEL 4 (LOWER JUGULAR)-
Superiorly-horizontal plane defined by inferior border of cricoid cartilage,
omohyoid muscle.
Inferiorly- Clavicle, 2cm cranial to sternoclavicular joint
Laterally(Posterior)-Lateral border of sternocleidomastoid muscle, sensory
branches of cervical plexus.
Medially-Medial border of SCM, Medial aspect of common carotid artery ,
scalenus muscle, Sternohyoid muscle.
11. LEVEL 5A (POSTERIOR TRIANGLE)-
Superiorly-Apex of convergence SCM and trapezius muscle
Inferiorly-Horizontal plane defined by inferior border of cricoid
Laterally(Posterior)-Anterior border of trapezius muscle
Medially-Lateral border of SCM
LEVEL 5B-
Superiorly-Horizontal plane defined by inferior border of
cricoid cartilage
Inferiorly-Clavicle
Laterally(Posterior)-Anterior border of trapezius muscle
Medially-Lateral border of SCM, sensory branches of cervical plexus
12. LEVEL 6 (ANTERIOR CERVICAL NODES/CENTRAL COMPARTMENT)-
Superiorly-Hyoid bone
Inferiorly-Superior edge of manubrium sternum, supra sternal notch
Laterally(Posterior)-Medial aspect of common carotid artery
» It has the pre-laryngeal (Delphian node- lies on cricothyroid membrane and drains
subgottic region of larynx and pyriform sinuses), pre-tracheal (lie in front of the trachea,
and drain thyroid gland and the trachea. Efferents from these nodes go to paratracheal, lower
internal jugular and anterior mediastinal nodes) and para-tracheal (drain the thyroid
lobes, subglottic larynx, trachea and cervical esophagus)
LEVEL 7 (SUPERIOR MEDIASTINAL)-
Superiorly-Superior edge of manubrium sternum
Inferiorly-Innominate artery (brachiocephalic artery)
Laterally-Innominate artery and common carotid artery
13. LYMPH NODES
ANATOMY-
Are small bean-shaped organs.
Each node has surrounding fibrous capsule around it & and a hilum at one side.
It receives many afferent vessels & gives efferent vessel from its hilum.
The lymph node is divided into an outer cortex and an inner medulla.
LYMPHADENOPATHY-
Lymphadenopathy refers to lymph nodes that are abnormal in either size(> 1cm), consistency or number.
Can be localized or generalized.
Cervical lymphadenopathy can be due to – infection (bacterial, viral, parasite, spirochetes, mycobacterium), inflammation,
immunologic (SLE, vasculitis-Kawasaki disease) proliferation of malignant lymphocytes or macrophages, infiltration by
metastatic malignant cells (neoplastic-leukemia, lymphoma, neuroblastoma, rhabdomyosarcoma, osteosarcoma,
nasopharyngeal carcinoma, thyroid cancers), Infiltration of lymph nodes by metabolite laden macrophages (lipid storage
diseases- Gaucher disease, Neimann-Pick disease).
14. Clinical Characteristics of lymph nodes
1) Consistency
-Stony hard: typical of cancer, usually metastatic
-Firm rubbery: can suggest lymphoma
-Soft: infection or inflammation
-Fluctuant : Suppurated nodes.
-Matted : . A group of nodes that feels connected and seems to move as a unit is said to be "matted." Nodes that are matted can
be either benign (e.g., tuberculosis, sarcoidosis or lymphogranuloma venereum) or malignant (e.g., metastatic carcinoma or
lymphomas).
2) Pain/Tenderness
When a lymph node rapidly increases in size, its capsule stretches and causes pain. Pain is usually the result of an inflammatory
process or suppuration, but pain may also result from hemorrhage into the necrotic center of a malignant node. The presence or
absence of tenderness does not reliably differentiate benign from malignant nodes.
3) Size
4) Location - anatomic location of localized adenopathy is sometimes helpful in narrowing the differential diagnosis.
16. FNAC
Safe, convenient, less invasive (than biopsy) and quicker reporting time.
Can be used to differentiate between metastatic, infectious, reactive and lymphomatous causes of lymphadenopathy.
If the LN are not palpable, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) can be used.
Overall sensitivity of FNAC is 92.7%, specificity 98.5%
Limitations of FNAC:-
—lack of proper tissue sample to run special studies like cytogenetics, flow cytometry, electron microscopy.
— the potential risk of seeding of tract with malignancy.
BIOPSY
Can be done by bedside or by open surgery, the preservation of nodal architecture is critical for proper diagnosis of
lymphadenopathy.
The diagnostic yield of biopsy can be maximized by obtaining an excisional biopsy of the largest and most abnormal node (which
is not necessarily the most accessible node).
17. CARCINOMA OF UNKNOWN/OCCULT PRIMARY
It represents a heterogenous disease entity characterized by the presence of
clinically overt metastatic disease in the absence of a clinically or radiologically
obvious primary tumor.
SITES - Nasopharynx, Tongue base, Tonsil, Pyriform fossa, Infrahyoid epiglottis etc.
NICE RECOMMENDATION(National institute for Health and care excellence)
a. Add USG guidance to FNAC or core biopsy
b. Consider having a cytopathologist or biomedical scientist to assess the adequacy of cytology sample.
c. FDG PET-CT (Fluorodeoxyglucose positron emission tomography) as first investigation to detect primary.
d. Consider using narrow band imaging.
e. Surgical diagnostic techniques like guided biopsy, tonsillectomy, tongue base mucosectomy.
18. ALGORITHM FOR INVESTIGATING AN UNKNOWN PRIMARY WITH NECK
METASTASIS
Patient presenting with a neck node
Comprehensive ENT examination
FNAC confirms squamous cell cancer
CT/MRI
FDG-PET/CT
Pan-endoscopy and bilateral tonsillectomy
45% reduction in unknown primary
19. NECK DISSECTION
Elective or prophylactic neck dissection - done in node negative patients
Therapeutic neck dissection – done for clinically positive nodes
American Academy Committee for Head and Neck Surgery and Oncology publicized a standard
classification system, according to which, there are 4 types of neck dissection –
†Radical(RND)
†Modified Radical(MRND)
†Extended Radical
†Selective(SND)
These different types of neck dissections refer to the amount and location
of nodes removed or the secondary structures removed or preserved.
As neck dissections can be therapeutic or prophylactic. Their indications
should be discussed at a multidisciplinary meeting based on their nodal
status (N1-3). Even in clinically node negative necks (N0), there is a risk of
microscopic nodal spread.
20. 1.Radical Neck Dissection
The radical neck dissection was first described in 1906 by Crile.
A radical neck dissection involves the removal of lymph nodes in levels I-V
in addition to removal of other three non-lymphatic structures:-
1. Sternocleidomastoid muscle
2. Internal Jugular Vein
3. Spinal Accessory Nerve
23. 2.Modified Radical Neck Dissection
Modified radical neck dissections remove levels I-V (similar to a radical neck dissection). It is
modified in the structures it preserves.
These modifications are described in relation to which structures (least 1 of the non lymphatic)
are preserved:-
Type I: Spinal accessory nerve is preserved.
(Indications- Clinically obvious lymph node metastases, SAN not involved
by tumor, Intraoperative decision)
Type II: Spinal accessory & internal jugular vein are preserved.
(Indications- Rarely planned, Intraoperative tumor found adherent to SCM,
but not IJV and SAN)
Type III (Bocca’s or Functional) : Spinal accessory &
internal jugular vein & sternocleidomastoid are preserved.
Neck dissection of choice for N0 neck.
25. 3.Selective Neck Dissection
Selective neck dissections (Also known as Elective neck dissection ) preserve one or more lymph
node levels.
Specific lymph node regions are selected based on the lymphatic drainage patterns from the
primary tumor site.
Other structures are preserved (similar to a Type III modified radical neck dissection).
» Supra-omohyoid SND (SOND): En-bloc removal of I-III
» Lateral SND : II-IV
» Posterolateral SND : II-V
»Anterior/Central SND : VI
Needs post-op Radiotherapy.
26. SUPRA-OMOHYOID NECK DISSECTION (SOHND)
» Most commonly performed SND
» Definition - En bloc removal of cervical lymph node groups I-III
Posterior limit is the cervical plexus and posterior border of the SCM
Inferior limit is the omohyoid muscle overlying the IJV
»Indications - Oral cavity carcinoma with NO neck
Boundaries - Vermillion border of lips to junction of hard and soft palate, circumvallate papillae
Subsites - Lips, buccal mucosa, upper and alveolar ridges, retromolar trigone, hard palate, and anterior 2/3 of the tongue
and floor of mouth.
BILATERAL SOHND
»Indications – Carcinoma anterior tongue
- Cutaneous squamous cell carcinoma of the cheek
- Melanoma (Stage I - 1.5 to 4mm) of the cheek
Carcinoma tongue and floor of mouth that approach the midline » SOHND + parotidectomy.
27. 4.EXTENDED RADICAL NECK DISSECTION
Any previous neck dissection with additional removal of one or more lymph node groups and /or non-lymphatic structures.
Indications –
LYMPHATIC STRUCTURES - Parapharyngeal (retropharyngeal), superior mediastinal,
perifacial (buccinator), and paratracheal LNs
NON- LYMPHATIC STRUCTURES –
Carotid artery
Skin
Platysma
Digastric muscle (usually the posterior belly)
Hypoglossal nerve
Vagus nerve
Sympathetic chain
Paraspinal muscles etc.
28. SUPERSELECTIVE NECK DISSECTION / NIDUSECTOMY(SSND) –
New surgical procedures for residual disease after chemoradiation .
Dissection of 1 or 2 levels.
It is done for disease those cannot be classified under the existing system.
COMMANDO (COMbined MAndibulectomy and Neck Dissection Operation) -
Done for intra-oral tumours (of tonsils, mandible, tongue, floor of mouth, gingiva etc).
It involves the resection of the primary tumour, a part of mandible and surrounding cervical lymph nodes.
This also requires a facial reconstruction to reshape the structures that are degenerated during the surgery.
E.g. for primary tongue carcinoma - It comprises of glossectomy and hemi-mandibulectomy together
with block dissection of cervical nodes.
29. Indications for Neck Dissection:-
-Node-positive necks: N1 (SND), N2a & N2b (MRND III/SND), N3 (MRNDI/RND).
-Node-negative necks: risk of occult metastasis >20% (oral cavity, pharynx).
For aerodigestive tumours:
Oral Cavity: SND I-III (consider SND I-IV for invasive oral tumour)
Larynx and Pharynx: SND II-IV
Oropharyngeal: SND II-IV
Hypopharyngeal: SND II-IV
For cutaneous tumours:
Posterior scalp & upper neck: SND II-V, post-auricular, suboccipital ("posterolateral SND").
Pre-auricular, anterior scalp, temporal: SND parotid, II, III, Va and external jugular nodes
("posterolateral SND").
Anterior and lateral face: SND parotid and facial nodes I-III.
31. Contra-indications for Neck Dissection:-
Absolute contra-indications-
Untreatable primary
Inoperable neck disease
Distant metastasis
Relative contra-indications-
Unfit for major surgeries
32. COMPLICATIONS OF NECK DISSECTION:-
IMMEDIATE :- (Usually due to inadequate planning)
Includes injury to local blood vessels (hemorrhage), nerves (marginal mandibular, spinal accessory nerve, cervical plexus, brachial plexus) and
thoracic duct injury.
EARLY :-
Hemorrhage: Needs evaluation of the extent of bleeding and occasionally may need re-exploration.
Lymph leak: When the drainage is of milky fluid and is persistently high > 100ml /day after 2days. A possibility of lymph leak
has to be considered.
Carotid blow out: A dreaded complication that occurs secondary to wound break down. If exposed, the carotids have to be
covered using vascularized flaps.
Facial oedema: A common occurrence usually settles down in 4-6 weeks.
DELAY :-
Dysphagia ( CN V, lX, X, Xl)
Shoulder weakness
Trismus
Wound infection
Fistulae
Devitalisation of the reconstructed flap
33. Decision for incision:-
Personal preference of surgeon
Patient factors – age, sex, general condition
Extent of disease on imaging
Adequate vascularization of skin flaps
Adequate exposure of field and level of LNs to be accessed
Adequate protection of major vessels
Cosmetic
Previous surgical scar
Previous radiotherapy
