Lymphatic drainage,Lymph Nodes;Lymphadenopathy;History;Embryology; classification;differential diagnosis;Lymphatics of head and neck BY DR. C. P. ARYA

1. DR. CHANDRA PRAKASH ARYA
B.Sc. B.D.S, M.D.S, P.M.S
LYMPHATIC
DRAINAGE OF HEAD
& NECK

2. CONTENTS
1. Introduction
2. Historical Perspective
3. Embryological Development
4. Functions of Lymphatic System
5. Components of Lymphatic System
6. Lymph Nodes of Head & Neck
7. Lymphatic Drainage
8. Applied Aspects
9. Lymphadenopathy
10.Clinical Assessment
11.Laboratory Investigations
12.Differential Diagnosis & Evaluation
13.Conclusion
14.Reference

3. INTRODUCTION
• The lymphatic system is the part of the immune system
comprising a network of conduits called lymphatic vessels
that carry a clear fluid called lymph in a unidirectional
pathway and eventually conveying them into the heart.
• Of all the body systems, the lymphatic system is perhaps the
least familiar to most people. Yet without it, neither the
circulatory system nor the immune system could function—
circulation would shut down from fluid loss, and the body
would be overrun by infection for lack of immunity.

4. INTRODUCTION
• The entire lymph from the head and neck drains ultimately into
the deep cervical nodes either directly or through the peripheral
nodes. The deep cervical nodes form a vertical chain situated
along the entire length of the internal jugular vein.
• The lymphatic system is an endothelium-lined network of blind
ended capillaries found in nearly all tissues, draining via
collecting vessels into large vascular trunks that eventually
empty via an evolutionarily conserved drainage point into the
blood circulatory system.

5. HISTORICAL PERSPECTIVE
• Hippocrates first described vessels containing “white blood” around
400 B.C.
• Gasparo Aselli re-identified lymphatic vessels in the 1600’s, noting the
presence of lipid-filled “milky veins” in the gut of a “well-fed” dog
(Aselli, 1627).
• Historically, the most widely accepted view of lymphatic development
was proposed by Sabin in the early twentieth century (Sabin 1902,
1904).
• Sabin’s Model:-The isolated primitive lymph sacs originate from
endothelial cells that bud from the veins during early development.
• The two jugular lymph sacs were proposed to develop in the junction
of the sub-clavian and anterior cardinal veins by endothelial budding
from the anterior cardinal veins.

6. HISTORICAL PERSPECTIVE
• The remaining lymph sacs originate from the mesonephric vein
and those in the dorsomedial edge of the Wolffian bodies in the
junction of the subclavian and anterior cardinal veins.
• The retroperitoneal lymph sac forms near the primitive inferior
vena cava and mesonephric veins; the cisterna chyli forms
near the Wolffian bodies; and the posterior lymph sacs appear
near the junctions of the primitive iliac veins and the posterior
cardinal veins.
• The peripheral lymphatic system originates from the primary
lymph sacs, then spreads by endothelial sprouting into the
surrounding tissues and organs, where local capillaries are
formed.

7. HISTORICAL PERSPECTIVE
 Schematic representation of the primitive lymphatic system showing the
primary lymph sacs in a 42-day-old human embryo, after Sabin (reprinted
from Human Embryology, by W.J. Larsen, 1993, Harcourt, NY; with
permission from Harcourt International).

8. HISTORICAL PERSPECTIVE
• Alternative Model / Centripetal Model :-proposed by Huntington
and McClure 1910.
• They suggested that the primary lymph sacs arise in the
mesenchyme, independent of the veins, and secondarily
establish venous connections.
• This model was supported by Schneider et al. 1999.
• Perhaps the most definitive evidence for a venous origin for
early lymphatic endothelial cells has come from the zebra
fish(Yaniv et al., 2006).
• Recent studies have shown that the zebra fish possesses a
lymphatic vascular system with many of the morphological,
molecular, and functional characteristics of the lymphatic's of
other vertebrates.

9. EMBRYONIC DEVELOPMENT
• Lymphatic tissues begin to develop by the end of the fifth week
of embryonic development. Lymphatic vessels develop from
lymph sacs that arise from developing veins, which are derived
from mesoderm.
• The first lymph sacs to appear are the paired jugular lymph sacs
at the junction of the internal jugular and subclavian veins. From
the jugular lymph sacs, lymphatic capillary plexuses spread to
the thorax, upper limbs, neck and head. Some of the plexuses
enlarge and form lymphatic vessels in their respective regions.
Each jugular lymph sac retains at least one connection with its
jugular vein, the left one developing into the superior portion of
the thoracic duct.

10. EMBRYONIC DEVELOPMENT
• The next lymph sac to appear is the unpaired retroperitoneal
lymph sac at the root of the mesentery of the intestine. It
develops from the primitive vena cava and mesonephric veins.
Capillary plexuses and lymphatic vessels spread from the
retroperitoneal lymph sac to the abdominal viscera and
diaphragm. The sac establishes connections with the cisterna
chyli but loses its connections with neighboring veins.
• The last of the lymph sacs, the paired posterior lymph sacs,
develop from the iliac veins. The posterior lymph sacs produce
capillary plexuses and lymphatic vessels of the abdominal wall,
pelvic region, and lower limbs. The posterior lymph sacs join the
cisterna chyli and lose their connections with adjacent veins.

11. EMBRYONIC DEVELOPMENT
• With the exception of the anterior part of the sac from which
the cisterna chyli develops, all lymph sacs become invaded by
mesenchymal cells and are converted into groups of lymph
nodes.
• The spleen develops from mesenchymal cells between layers
of the dorsal mesentery of the stomach. The thymus arises as
an outgrowth of the third pharyngeal pouch.

12. FUNCTIONS OF LYMPHATIC
SYSTEMS
• The lymphatic system has multiple interrelated functions
i. It is responsible for the removal of interstitial fluid from
tissues
ii. It absorbs and transports fatty acids and fats as chyle from
the digestive system
iii. It transports white blood cells to and from the lymph nodes
into the bones
iv. The lymph transports antigen-presenting cells, such as
dendritic cells, to the lymph nodes where an immune
response is stimulated.

13. FUNCTIONS
Fat absorption
Lymph vessels called lacteals are in the beginning of the
gastrointestinal tract, predominantly in the small intestine. While
most other nutrients absorbed by the small intestine are passed on
to the portal venous system to drain via the portal vein into the liver
for processing, fats (lipids) are passed on to the lymphatic system
to be transported to the blood circulation via the thoracic duct.
(There are exceptions, for example medium-chain triglycerides are
fatty acid esters of glycerol that passively diffuse from the GI tract
to the portal system.) The enriched lymph originating in the
lymphatics of the small intestine is called chyle. The nutrients that
are released to the circulatory system are processed by the liver,
having passed through the systemic circulation.

14. FUNCTIONS
Immune function
The lymphatic system plays a major role in body's immune
system, as the primary site for cells relating to adaptive immune
system including T-cells and B-cells. Cells in the lymphatic system
react to antigens presented or found by the cells directly or by
other dendritic cells. When an antigen is recognized, an
immunological cascade begins involving the activation and
recruitment of more and more cells, the production of antibodies
and cytokines and the recruitment of other immunological cells
such as macrophages.

15. COMPONENTS OF LYMPHATIC SYSTEMS
1. Lymph:
– a fluid similar to plasma
– does not have plasma proteins
- the recovered fluid
2. Lymphatic vessels (lymphatics):
– network that carries lymph from peripheral tissues to the
venous system.
3. Lymphoid tissues:
- composed of aggregates of Lymphocytes, phagocytes, and
other immune system cells that populate many organs of the body
4. Lymphoid organs:
– found throughout the body
- in which these cells are especially concentrated and which are
set off from surrounding organs by connective tissue capsules.

16. LYMPH NODES OF HEAD & NECK

17. LYMPH NODES
• The lymphatic system functions to drain tissue fluid, plasma
proteins and other cellular debris back into the blood stream,
and is also involved in immune defence. Once this collection of
substances enters the lymphatic vessels, it is known as lymph.
Lymph is subsequently filtered by lymph nodes and directed
into the venous system.
• Lymph nodes are peripheral lymphoid organs connected to the
circulation by a afferent & efferent lymphatics.
• These are ovoid or bean shaped nodular formation composed
of dense accumulation of lymphoid tissue ,vary in size from 2 to
20mm & average of 15mm in longitudinal diameter.
• There are about 800 lymph nodes in the body and around 300
are located in head and neck.

18. STRUCTURE OF LYMPH NODES
Structure –
•A lymph node is an elongated or bean-shaped structure,
usually less than 3 cm long, often with an indentation called
the hilum on one side.
•It is enclosed in a fibrous capsule with extensions
(trabecular) that incompletely divide the interior of the node
into compartments.
•The interior consists of
a stroma of reticular connective tissue (reticular fibers and
reticular cells)
a parenchyma of lymphocytes and antigen-presenting cells.
•Between the capsule and parenchyma is a narrow space
called the subcapsular sinus, which contains reticular fibers,
macrophages, and dendritic cells.

19. STRUCTURE OF LYMPH NODES
• The parenchyma is divided into an outer cortex and, near the
hilum, an inner medulla.
• The cortex consists mainly of ovoid lymphatic nodules.
• When the lymph node is fighting a pathogen, these nodules
acquire light-staining germinal centers where B cells multiply
and differentiate into plasma cells.
• The medulla consists largely of a branching network of
medullary cords composed of lymphocytes, plasma cells,
macrophages, reticular cells, and reticular fibers.
• The lymph node is a “bottleneck” that slows down lymph flow
and allows time for cleansing it of foreign matter.
• The macrophages and reticular cells of the sinuses remove
about 99% of the impurities before the lymph leaves the node.
• On its way to the bloodstream, lymph flows through one lymph
node after another and thus becomes quite thoroughly cleansed
of most impurities.

20. STRUCTURE OF LYMPH NODES

21. FORMATION OF LYMPH
• Blood supplies nutrients
and important
metabolites to the cells
of a tissue and collects
back the waste products
they produce, which
requires exchange of
respective constituents
between the blood and
tissue cells. This
exchange is not direct,
but instead occurs
through an intermediary
called interstitial fluid,
which occupies the
spaces between cells.

22. FORMATION OF LYMPH
• As the blood and the surrounding cells continually add and remove
substances from the interstitial fluid, its composition continually changes.
Water and solutes can pass between the interstitial fluid and blood via
diffusion across gaps in capillary walls called intercellular clefts; thus, the
blood and interstitial fluid are in dynamic equilibrium with each other.
• Interstitial fluid forms at the arterial (coming from the heart) end of
capillaries because of the higher pressure of blood compared to veins,
and most of it returns to its venous ends and venules; the rest (up to
10%) enters the lymph capillaries as lymph. Thus, lymph when formed is
a watery clear liquid with the same composition as the interstitial fluid.
However, as it flows through the lymph nodes it comes in contact with
blood, and tends to accumulate more cells (particularly, lymphocytes)
and proteins.

23. FLOW OF LYMPH
Lymph takes the following
route from the tissues
back to the bloodstream:
Lymphatic capillaries->
collecting vessels->six
lymphatic trunks ->two
collecting ducts-
>subclavian veins.
Thus, there is a continual
recycling of fluid from
blood to tissue fluid to
lymph and back to the
blood.

24. FLOW OF LYMPH
Path of lymph flow through a lymph node
Afferent lymphatics[ afferent to bring to] carry lymph to the lymphnode
from peripheral tissues. The afferent lymphatics penetrate the capsule of
the lymph node on the side opposite to hilum
The afferent vessels deliver lymph to the subscapular space , a mesh work
of reticular fibres, macrophages , and dentritic cells. Dendritic cells are
involved in the intitiation of immune response.
Lymph next flows into the outer cortex , which contains B cells with
germinal centres that resemble those of lymphoid nodule

25. FLOW OF LYMPH
Lymph then flows through lymph sinuses in the deep cortex, which is
dominated by T cells.
Lymph continous into the medullary sinus at the core of the lymph
node .This region contain B cells and plasma cells.
Efferent lymphatics [efferent, to bring out] leave the lymph node at the
hilum. These vessels collect lymph from the medullary sinus and carry
it towards the venous circulation.

26. FUNCTIONS OF LYMPH
• Play an important role in the defence mechanism of the body.
They filter out micro-organisms (such as bacteria) and foreign
substances such as toxins, etc.
• Major functions are :
I. Lymphopoiesis
II. Filtration of lymph
III. Processing of antigens
• Multiplication of B cells and T cells from preexisting lymphocytes
in response to antigens.
• Antibodies produced are carried to circulation indirectly helping to
mount an immune response.

27. CLASSIFICATION OF LYMPH
NODES

28. CLASSIFICATION

29. CLASSIFICATION

30. CLASSIFICATION

31. CLASSIFICATION

32. CLASSIFICATION

33. CLASSIFICATION

34. CLASSIFICATION

35. CLASSIFICATION

36. CLASSIFICATION

37. CLASSIFICATION

38. CLASSIFICATION

39. LYMPHATIC DRAINAGE
• The lymph nodes of the head and neck can be divided into two
groups; a superficial ring of lymph nodes, and a vertical group of
deep lymph nodes.
• The outer, superficial, ring consists of the occipital, preauricular
(parotid), submandibular and submental nodes, and the inner,
deep, ring is formed by clumps of mucosa associated lymphoid
tissue (MALT) located primarily in the naso- and oro-
pharynx(Waldeyer's ring).

40. WALDEYER’S RING

41. WALDEYER’S RING
Waldeyer’s tonsillar ring refers to the
collection of lymphatic tissue
surrounding the superior pharynx. This
lymphatic tissue responds to pathogens
that may be ingested or inhaled. The
tonsils that make up the ring are as
follows:
Lingual tonsil– located on the
posterior base of the tongue to form the
antero-inferior part of the ring.
Palatine tonsils– located on each side
between the palatoglossal and
glossopharyngeal arches. These are
the common ‘tonsils’ that can be seen
within the oral cavity. They form the
lateral part of the ring.
Tubal tonsils– these are located
where each Eustachian tube opens into
the nasopharynx and form the lateral
part of the ring.
Pharyngeal tonsil– also called the
nasopharyngeal/adenoid tonsil, located
in the roof of the nasopharynx, behind
the uvulva and forms the postero-
superior part of the ring.

42. LYMPHATIC DRAINAGE
• The vertical chain consists of superior and inferior groups of
nodes related to the carotid sheath.
• All lymph vessels of the head and neck drain into the deep
cervical nodes, either directly from the tissues or indirectly via
nodes in outlying groups.
• Lymph is returned to the systemic venous circulation via either
the right lymphatic duct or the thoracic duct.

43. LYMPHATIC DRAINAGE OF EXTERNAL NOSE

44. LYMPHATIC DRAINAGE OF NASAL CAVITY
• Lymph vessels from the
anterior region of the
nasal cavity pass
superficially to join those
draining the external nasal
skin, and end in the
submandibular nodes.
• The rest of the nasal
cavity, paranasal sinuses,
nasopharynx and
pharyngeal end of the
pharyngotympanic tube,
all drain to the upper deep
cervical nodes either
directly or through the
retropharyngeal nodes.
• The posterior nasal floor
probably drains to the
parotid nodes.

45. LYMPHATIC DRAINAGE OF TONGUE
• The lymphatic drainage of
the tongue can be divided
into three main regions,
marginal, central and dorsal.
• The anterior region of the
tongue drains into marginal
and central vessels, and the
posterior part of the tongue
behind the circumvallate
papillae drains into the
dorsal lymph vessels.
• The more central regions
drain bilaterally into sub-
mental and sub-mandibular
nodes.

46. LYMPHATIC DRAINAGE OF TEETH
•The lymph vessels
from the teeth usually
run directly into the
ipsi-lateral
submandibular lymph
nodes.
•Lymph from the
mandibular incisors,
however, drains into
the sub mental lymph
nodes.
•Occasionally, lymph
from the molars may
pass directly into the
jugulo-digastric group
of nodes.

47. APPLIED ASPECT
• Block dissection of neck is sometimes envisaged for removal of all
cervical lymph nodes to arrest metastasis from carcinoma in region of
mouth and lips.
• When the radical block dissection is combined with resection of area of
lesion(oral cavity or mandible) it is called commando operation
• The presence of rich network of lymphatics and of loose areolar tissue is
responsible for enormous swelling of tongue in acute glossitis.
• Carcinoma of tongue is quite common. Affected side of tongue is removed
surgically. All the deep cervical lymph nodes are removed surgically; block
dissection of neck because recurrence of malignancy occurs in lymph
nodes
• Carcinoma of posterior one third of tongue is more common due to
bilateral lymphatic spread.
• Deep cervical lymph nodes lie along internal jugular vein. These become
adherent in malignancy to the vein. So, during operation along with lymph
nodes vein is also removed.

48. APPLIED ASPECTS
• Neck infections in front of pre vertebral fascia in retropharyngeal space
usually arise from suppuration i.e. formation of pus in retropharyngeal
lymph nodes .pus forms an acute retropharyngeal abscess.
• Parotid abscess may be formed by suppuration of parotid lymph nodes
draining in infected area.
• In malignancy of parotid glands cervical lymph nodes are enlarged.
• When a lymph node is under challenge from a foreign antigen, it may
become swollen and painful to the touch— a condition called
lymphadenitis.
• Commonly palpated and accessible lymph nodes are – the cervical,
axillary, and inguinal.
• Lymph nodes are common sites of metastatic cancer because cancer
cells from almost any organ can break loose, enter the lymphatic
capillaries, and lodge in the nodes.
• Lymphadenopathy is a collective term for all lymph node diseases

49. LYMPHADENOPATHY
• Lymphadenopathy or adenopathy is disease of the lymph nodes, in
which they are abnormal in size, number, or consistency.
Lymphadenopathy of an inflammatory type (the most common type)
is lymphadenitis, producing swollen or enlarged lymph nodes.
• Inflammation of the lymphatic vessels is known as lymphangitis.
Infectious lymphadenitis affecting lymph nodes in the neck are often
called scrofula.
• It may be an incidental finding in patients being examined for
various reasons, or it may be a presenting sign or symptom of the
patient's illness.
• Soft, flat, submandibular nodes (<1 cm) are often palpable in
healthy children and young adults;
• Healthy adults may have palpable inguinal nodes of up to 2 cm,
which are considered normal.

50. LYMPHADENOPATHY
CLASSIFICATION
By extent:
Localized lymphadenopathy:
• Due to localized spot of infection e.g., an infected spot on the scalp
will cause lymph nodes in the neck on that same side to swell up.
• implies involvement of a single anatomic area.
• The site of localized or regional adenopathy may provide a useful
clue about the cause. e.g. Occipital adenopathy often reflects an
infection of the scalp, and pre auricular adenopathy accompanies
conjunctival infections and cat-scratch disease.
Generalized lymphadenopathy:
• Due to a systemic infection of the body e.g., influenza or secondary
syphilis
• It has been defined as involvement of three or more noncontiguous
lymph node areas

51. LYMPHADENOPATHY
• Generalized lymphadenopathy is frequently associated with
nonmalignant disorders such as
i. infectious mononucleosis [Epstein-Barr virus (EBV) or
cytomegalovirus (CMV)], toxoplasmosis, AIDS, other viral
infections,
ii. systemic lupus erythematosus (SLE), and
iii. mixed connective tissue disease.
• Acute and chronic lymphocytic leukemias and malignant
lymphomas also produce generalized adenopathy in adults.
Persistent generalized lymphadenopathy (PGL):
persisting for a long time, possibly without an apparent cause

52. LYMPHADENOPATHY
• By malignancy: Benign
lymphadenopathy is
distinguished from
malignant causes which
mainly refer to
lymphomas or lymph
node metastasis.
• By localization:
including hilar
lymphadenopathy.
• Dermatopathic
lymphadenopathy:
lymphadenopathy
associated with skin
disease.

53. CLINICAL ASSESSMENT
•The physician will be aided in the pursuit of an
explanation for the lymph-adenopathy by-
a. a careful medical history,
b. physical examination,
c. selected laboratory tests, and
d. an excisional lymph node biopsy.
Medical History :-
•It should reveal the setting in which
lymphadenopathy is occurring.
•Symptoms such as sore throat, cough, fever, night
sweats, fatigue, weight loss, or pain in the nodes
should be sought.

54. CLINICAL ASSESSMENT
• The patient's age, sex, occupation, exposure to pets, sexual
behavior, and use of drugs such as diphenylhydantoin are other
important historic points.
• For example, children and young adults usually have benign (i.e.,
nonmalignant) disorders that account for the observed
lymphadenopathy such as viral or bacterial upper respiratory
infections; infectious mononucleosis; toxoplasmosis; and, in some
countries, tuberculosis.
• In contrast, after age 50, the incidence of malignant disorders
increases and that of benign disorders decreases.

55. CLINICAL ASSESSMENT
Physical examination :-
It can provide useful clues such as
• the extent of lymphadenopathy (localized or generalized),
• size of nodes,
• texture,
• presence or absence of nodal tenderness,
• signs of inflammation over the node,
• skin lesions, and
• splenomegaly.

56. CLINICAL ASSESSMENT
• Size of the lymph Nodes <1.0 cm2 in area (1.0 cm x 1.0 cm or
less) are almost always secondary to benign, nonspecific
reactive causes
• In one retrospective analysis of younger patients (9–25 years)
who had a lymph node biopsy, a maximum diameter of >2 cm
served as one discriminant for predicting that the biopsy would
reveal malignant or granulomatous disease.
• Patients with node(s) 1.0 cm2 should be observed after
excluding infectious mononucleosis and/or toxoplasmosis
unless there are symptoms and signs of an underlying systemic
illness.

57. CLINICAL ASSESSMENT
• The texture of lymph nodes may be described as soft, firm,
rubbery, hard, discrete, matted.
• It may be tender or non-tender.
• It may be movable or fixed.
• Tenderness is found when the capsule is stretched during rapid
enlargement, usually secondary to an inflammatory process.
• Some malignant diseases such as acute leukemia may produce
rapid enlargement and pain in the nodes.
• E.g. Nodes involved by lymphoma tend to be large, discrete,
symmetric, rubbery, firm, mobile, and non tender.

58. CLINICAL ASSESSMENT
• Nodes containing metastatic cancer are often hard, non-tender,
and non-movable because of fixation to surrounding tissues.
• The co-existence of splenomegaly in the patient with
lymphadenopathy implies a systemic illness such as-
infectious mononucleosis,
lymphoma,
acute or chronic leukemia,
SLE,
sarcoidosis,
toxoplasmosis,
cat-scratch disease, or
other less common hematologic disorders.

59. CLINICAL ASSESSMENT
Palpation of Lymph Nodes –
• Lymph node and chain palpation starts with the parotid and pre
auricular area which may also be palpated bimanually.
• Palpating with light finger pressure against underlying firm tissues
(bone or muscle), or bimanually where appropriate.
• The head and neck lymph examination continues down the
mandible to the Submandibular region where bilateral palpation
proceeds forward to the Submental nodes just under the chin.
• With the patient seated upright, head tipped slightly forward, the
cervical lymphatic chains are palpated against the
sternocleidomastoid muscle.
• Superficial cervical lymph nodes are found along the anterior
border, and deep superior and inferior chains found along the
posterior border.

60. CLINICAL ASSESSMENT

61. CLINICAL ASSESSMENT

62. LABORATORY INVESTIGATIONS
• The laboratory evaluation of lymphadenopathy must be directed by
the history and physical examination and is based on the size and
other characteristics of the nodes and the overall clinical
assessment of the patient. When a laboratory evaluation is
indicated, it must be driven by the clinical evaluation.
• The following studies should be considered for chronic
lymphadenopathy (>3 wk):
CBC count, including a careful evaluation of the peripheral blood
smear Lactate dehydrogenase (LDH) and uric acid.
B henselae (catscratch) serology if exposed to a cat
Tuberculosis skin test (TST) and interferon-gamma release assay
(eg, Quantiferon Gold)

63. LABORATORY INVESTIGATIONS
• Fine needle aspiration and core needle biopsy yield small
samples with limited ability to perform flow cytometry and
chromosomal analysis; most pediatric hematologists and
pathologists prefer excisional biopsy. (However, a retrospective
study by Sher-Locketz et al reported that fine-needle aspiration
biopsy, as performed through an efficient laboratory-managed
service, proved to be an acceptable replacement for surgical
biopsy in the triage of pediatric lymphadenopathy.)
• Excisional biopsy also has limitations and may yield a definitive
diagnosis in only 40-60% of patients because of inadequate
specimen size, improper handling, or node-sampling error (eg,
Hodgkin lymphoma) may be associated with reactive changes in
surrounding nodes; sampling more accessible nodes may miss
the underlying malignancy.

64. LABORATORY INVESTIGATIONS
• Chest Radiography may be helpful in elucidating mediastinal
adenopathy and underlying diseases affecting the lungs, including
tuberculosis, coccidioidomycosis, lymphomas, neuroblastoma,
histiocytoses, and Gaucher disease, primary lung cancer, or
metastatic cancer.
• Ultrasonography may be helpful in documenting the extent of
lymph node involvement and any changes in the lymph nodes. In
children with inguinal adenopathy or abdominal complaints,
ultrasonography of the abdomen, CT scan of the abdomen, or both
may be indicated. Ultrasonography is rarely of diagnostic value for
lymphadenopathy in childhood, even with advanced techniques.
• Evaluation of the Intranodal Vascularity Index is an effective
means of diagnosing metastatic and tuberculous lymph nodes in
patients with cervical lymphadenopathy.

65. LABORATORY INVESTIGATIONS
• Using ultrasonographic images from 347 patients with palpable
cervical lymph nodes, a customized computer program was used
to quantify the intranodal vascularity index. With regard to
distinguishing metastatic and tuberculous lymph nodes, the
index was found to have a sensitivity and specificity of 80% and
73%, respectively; positive and negative predictive values of
91% and 51%, respectively; and an overall accuracy of 68%,
when the cutoff vascularity index was 22%.
• Supraclavicular adenopathy, with its high associated rate of
serious underlying disease, may be an indication for Computed
Tomography (CT) scan of the chest, abdomen, or both.
• Positron-emission tomography (PET) scanning is not helpful
as a screening tool as benign and malignant conditions may
cause intense uptake. However, PET scanning is helpful in the
staging of lymphomas once a diagnosis is made.

66. LABORATORY INVESTIGATIONS
• Diffusion-weighted Magnetic Resonance Imaging (MRI) can
be used to differentiate malignant from benign mediastinal
lymphadenopathy in children.
• In the study, which included 29 children with mediastinal
lymphadenopathy, patients were assessed with single-shot echo
planar diffusion-weighted MRI, with the mean apparent diffusion
coefficient (ADC) for the malignant condition being significantly
below that for benign mediastinal lymphadenopathy. However,
although this study may represent an important advance in the
imaging of mediastinal / hilar lymphadenopathy, the results must
be confirmed before the routine use of this technique can be
recommended.

67. LABORATORY INVESTIGATIONS
• Shear-wave elastography (SWE) is an effective imaging modality
for distinguishing benign from malignant superficial
lymphadenopathy when the distinction cannot be made using
conventional ultrasonography. The investigators found that in
malignant lesions, the maximum and mean elastic modulus, as
well as the standard deviation of the elastic modulus, were
significantly higher than for benign lesions.
• Endobronchial ultrasound-guided transbronchial needle
aspiration (EBUS-TBNA) is a widespread technique for tissue
sampling from hilar and mediastinal lymph nodes; however, the
predominant finding in routine care is a nondiagnostic cytology in
more than 70% of patients.
• Some studies indicated that, as in adults, EBUS-TBNA and
endoscopic ultrasonography with an echobronchoscope-guided
fine-needle aspiration (EUS-B-FNA) can be safely and
effectively used in children with mediastinal lymphadenopathy,
providing a good diagnostic yield.

68. LABORATORY INVESTIGATIONS
ADVANCED IMAGING TECHNIQUE
• Planar lympho-scintigraphy
• Hybrid SPECT/CT imaging
• Dynamic contrast – enhanced MR imaging
• Ultra-small super-paramagnetic iron oxide (USPIO) enhanced
• Gadolinium enhanced MRI

69. DIFFERENTIAL DIAGNOSIS & EVALUATION
• Although the finding of lymphadenopathy sometimes raises fears
about serious illness, it is, in patients seen in primary care
settings, usually a result of benign infectious causes. Most
patients can be diagnosed on the basis of a careful history and
physical examination.
• Localized adenopathy should prompt a search for an adjacent
precipitating lesion and an examination of other nodal areas to
rule out generalized lymphadenopathy.
• In general, lymph nodes greater than 1 cm in diameter are
considered to be abnormal. Supraclavicular nodes are the most
worrisome for malignancy. A three- to four-week period of
observation is prudent in patients with localized nodes and a
benign clinical picture.
• Generalized adenopathy should always prompt further clinical
investigation. When a node biopsy is indicated, excisional biopsy
of the most abnormal node will best enable the pathologist to
determine a diagnosis.

70. DIFFERENTIAL DIAGNOSIS & EVALUATION

71. DIFFERENTIAL DIAGNOSIS & EVALUATION

72. DIFFERENTIAL DIAGNOSIS & EVALUATION

73. CONCLUSION
Lymphadenopathy is defined as lymph nodes that are abnormal in
size, consistency or number. The extent of lymphadenopathy is
defined as localized, regional or generalized. Lymphadenopathy is
commonly encountered by physicians in clinical practice and requires
a comprehensive evaluation. When initiating a work-up, the physician
should pay close attention to the size, location, consistency and
number of enlarged lymph nodes, as well as to the patient's age and
any associated symptoms. Lymphadenopathy may be due to
malignancy, hypersensitivity, infection, collagen vascular disease,
atypical lymphoproliferative disorders, granulomatous diseases and
other miscellaneous causes.
The lymphatic system and its organs are widespread and scattered
throughout the body. It functions to service almost every region of the
body. Because the vessels of the lymphatic system span the entire
body it becomes an easy portal for the spread of cancer and other
diseases, which is why disorders and diseases of this system can be
so devastating.

74. REFERENCE
King, D; Ramachandra, J; Yeomanson, D (2 January 2014).
"Lymphadenopathy in children: refer or reassure?". Archives of
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Maha Torabi, MD;, Suzanne L. Aquino; and Mukesh G. Harisinghani
(2004-09-01). "Current Concepts in Lymph Node Imaging". J Nucl
Med. 45 (9): 1509–1518.
Laurence Knott. "Generalised Lymphadenopathy". Patient UK.
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Grant's Atlas of Anatomy,13th Ed.
Gray's Anatomy – 40th Ed.
Anatomy of the Human Body - Henry Gray

75. REFERENCE
Saladin: Anatomy & Physiology: The Unity of Form and Function,
3rd Edition
Embryology Atlas , John F Neas
Life Map – Embryonic development & stem cell compendium
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Robert Ferrer, M.D., M.P.H., University of Texas Health Sciences
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76. DR. CHANDRA PRAKASH ARYA
THANK
YOU