Lymphatic system

Question 1

Basic function of the lymphatic system

Answer 1

Primary site of immune response
Maintains body’s fluid homeostatic
balance
Production and distribution of lymphocytes
Phagocytosis
Absorption of fats and fat-soluble substances from intestinal tract
Unwanted function (pathway for spread of malignancy)

Question 2

Components of the Lymphatic system

Answer 2

Lymph fluid, vessels, trunks, ducts, Lymph nodes, thymus, spleen
aggregations of lymph node
Tonsils AKA Palatine tonsils
adenoids aka pharyngeal tonsils
Peyer patches, appendix

Question 3

What is lymph?

Answer 3

Goes in one direction
Latin = clear water sometimes yellow-tinged tissue fluid
that contains WBC’s, mainly T and B
lymphocytes.
Also contains salts, glucose, fats, water but
NO RBC’s.
Lymph also contains proteins and
transports back into bloodstream
Lymph (chyle) from intestine contains
fat, fatty acids
Body produces three liters per day
Movement of lymph along the system
depends on CV system’s pump so flow is
more sluggish than blood
Assisted by the skeletal muscles as well as
the smooth muscles located in the
lymphatic vessels

Question 4

Lymph nodes: filtration
& purification stations

Answer 4

Kidney-shaped aggregations of lymphatic tissue
There are around 600 lymph nodes in the body
Structural anatomy:
Hilum: slight depression on the side where vessels enter
Capsular shell (painful when stretched)
Trabecula provides support
Cellular makeup:
Macrophages or “destroyers”
Lymphocytes- packed in follicles T cells and B cells
Removes foreign cells and debris from lymph
lymph traverses one or more lymph nodes
before it enters the bloodstream
Sentinel lymph node: first lymph node draining
cancer

Question 5

Thymus: endocrine gland
and lymphatic organ

Answer 5

Soft, triangular, comprised of 2 lobes &
located in superior mediastinum over
heart
Responsible for production and
maturation of T lymphocytes
Atrophies with age (age 12) and
replaced with fat (Only 15% active by age 50)
Involution of the thymus has been linked
to loss of immune function in the elderly,
susceptibility to infection and cancer Immunodeficiency from congenital
defects

Question 6

Spleen

Answer 6

Largest lymphatic organ
Long axis lies behind and parallel to 10th rib
in Mid axillary line. (LUQ)
12 cm long, 7cm wide, 7oz
Extends from ribs 9-11 and touches
stomach, left kidney, splenic flexure of colon
and tail of pancreas.
Weighs 150g (400-500g = splenomegaly)
Half the size of the heart
Extension superiorly blocked by diaphragm,
so enlargement displaces lower pole
downward.
Usually nontender if enlarged.
The presence of a palpable spleen is almost
always abnormal unless patient is slender.
Main function: filter blood, removes
old/malformed/damaged red blood cells; also
fights infection, stores blood

Question 7

Differential Diagnosis : Splenomegaly

Answer 7

Lymphoproliferative/myeloproliferative:
Leukemia, lymphoma
Vascular congestion: CHF, cirrhosis
(portal hypertension)
Hematologic defects: hemolytic anemia,
ITP, spherocytosis, thalassemia major,
polycythemia, sickle cell
Systemic: Sarcoidosis, SLE, RA,
primary biliary cholangitis
Infectious: Epstein Barr Virus (EBV),
Cytomegalovirus (CMV), Human
Immune Deficiency Virus (HIV),
Hepatitis, Rocky Mountain Spotted
Fever RMSF, syphilis, malaria,
endocarditis, abscess, typhoid, TB,
leishmaniasis, schistosomiasis
Misc: trauma, cyst

Question 8

Patient Education Splenectomy

Answer 8

Patients undergoing splenectomy should
be vaccinated against:*
* Influenza vaccine
* Tdap vaccine
* Hib vaccine
* Pneumococcal vaccines (both types)
* Meningococcal vaccines (both types)
* Zoster vaccine
* HPV vaccine
* MMR vaccine
* Varicella vaccine
* COVID
Caution against contact sports or other
activities that may cause force on LUQ
Malaria prophylaxis before travel
Medi-alert bracelet/wallet card
Alert practitioner with any fever causing
illness

Question 9

What is lymphadenopathy?

Answer 9

An abnormality in the size, consistency or number of lymph nodes
Caused by invasion or propagation of: Inflammatory cells, Neoplastic cells
Typically explained by identifiable regional injury or infection
Classified as:
General: enlargement in 2 or more
noncontiguous areas (serious
infections, autoimmune,
disseminated malignancies)… NO
Localized: only one area is
involved ; ¾ of cases …. in kids
Distinguishing between localized and
generalized LAD is important in
formulating your differential diagnosis!

Question 10

Physical Exam of the Lymphatic System

Answer 10

Evaluation of lymphaadenopathy
Inspection,
Palpitation
Use pads of second, third and fourth fingers
Use circular motion
Perform bilaterally simultaneously and check for asymmetric findings
Press lightly at first, then increase pressure
Best done without gloves

Question 11

Why do lymph nodes enlarge?

Answer 11

Increase in number of benign lymphocytes and
macrophages in response to antigens known as
reactive LAD
Infiltration of inflammatory cells in viral or
bacterial infection
In situ proliferation of malignant lymphocytes or
macrophages such as lymphoma/leukemia
Infiltration by metastatic malignant cells
Rarely, medications cause enlargement

Question 12

Superficial Lymph Nodes

Answer 12

Palpable if enlarged:
Cervical, Axillary, Epitrochlear, Inguinal

Question 13

Deeper Lymph nodes

Answer 13

Tracheal/Bronchial
Hilar/mediastinal
Mesenteric nodes
Preaortic nodes
Iliac nodes
Popliteal nodes

Question 14

Cervical Lymph Nodes: Anterior Triangle

Answer 14

Submental: drains central lip, floor of mouth and tip of tongue. Often infectious etiology
Submandibular: drains lips, mouth,tongue, anterior face, submaxillary salivary gland, conjunctivae. Often infectious etiology
Anterior superficial cervical chain:Drains part of parotid and inferior
auricle.Common cause is strep throat
Deep cervical chain: passes into thoracic duct or right lymphatic duct; lymph from entire scalp eventually drains into deep cervical nodes

Question 15

Cervical Lymph Nodes: Posterior Triangle

Answer 15

Posterior cervical: drains scalp/neck, skin of
arms/pecs, thorax and cervical and axillary nodes
Common cause: Epstein Barr Virus
Supraclavicular: highest risk of malignancy.Right-sided indicates CA in mediastinum, lungs, esophagus; Left-sided (Virchow’s node) indicates
CA of testes, ovaries, kidneys, pancreas,stomach, GB or prostate
Jugulodiagastric (retropharyngeal or tonsillar)
drains tonsil, tongue, pinna and parotid
Occipital: drains occipital scalp. Common cause:
Tinea Capitus

Question 16

Other Superficial lymph nodes

Answer 16

Preauricular: drains eyelids, conjunctivae, temporal region and pinna
Postauricular: drains temporoparietal scalp, pinna, external auditory meatus
Superficial parotid: drains lateral face, including eyelids; drains into deep cervical nodes
Epitrochlear nodes: drains ulnar aspect of forearm and hand

Question 17

Axillary lymph nodes and LAD causes

Answer 17

Drains arm, thoracic wall, and breast

Most are reactive and benign
Staph/strep (cellulitis,mastitis)
Cat Scratch
Silicone prosthesis
HIV
Rheumatoid Arthritis
Breast carcinomas
Lymphomas/leukemia
Melanoma

Question 18

Periumbilical (Sister Mary Joseph) and LAD causes

Answer 18

Abdominal and pelvic neoplasm

Gastrointestinal malignancies (gastric, colon, pancreatic cancer)
GYN cancers (ovarian, uterine)
Appendix, lung, urinary or prostate cancer (rare)

Question 19

Inguinal Nodes and LAD causes

Answer 19

penis, scrotum, vulva, vagina, perineum, gluteal region, lower abdominal wall, and lower anal canal
Nodes enlarged up to 1-2 cm in diameter in many healthy adults
Most common etiologies:
Low suspicion of malignancy
STIs
Insect bite
Bacterial/fungal infection
Lymphomas
Penile, vulvar cancers
Melanoma
Infections of the leg/foot

Question 20

Lymph nodes commonly associated with malignancy

Answer 20

Supraclavicular: highest risk of malignancy.
Right-sided indicates CA in the mediastinum, lungs, and esophagus;
Left-sided (Virchow’s node) indicates CA of testes, ovaries, kidneys, pancreas, stomach, GB, or prostate

Low suspicious for malignancy= Inguinal LN

Cervical LN=Head and Neck malignancy

Question 21

If lymph nodes are enlarged, describe???

Answer 21

Location
Size/shape: Normal if up to 1-1.5cm (always use metric)
Tenderness:
Due to capsular stretching.Usually from infection, or inflammation.
Pain in the node after drinking alcohol suggests Hodgkin Lymphoma
Consistency:
Hard=malignant, firm/rubbery suggest lymphoma.
Soft=infections/inflammatory processes
Shotty: small, hard-ish, of no concern
Matting:
Group of nodes that feel connected and seem to move as a unit. It can be benign (TB, sarcoid) or malignant.
Mobility: fixed vs mobile
Surface characteristics: redness, warmth
Symmetry

Question 22

Localized LAD: Evaluation

Answer 22

Dependent on history and physical
Always CBC with differential
Other tests based on clinical suspicion
EG:
 Kids with URI Symptoms: CBC with differential, ESR, heterophile antibody,IGM for cytomegalovirus and toxoplasmosis
 Adult with weight loss, fever, night sweats: CBC with differential, chest radiograph, tuberculin skin test
 Other things based on history; eg, tularemia in a hiker, sporotrichosis in a gardener
“Watchful waiting” ~ 3-4 weeks Ultrasound, biopsy if no resolution

Question 23

Bartonella henselae: Cat scratch disease
Characteristics

Answer 23

Following cat bite/scratch
Typically occurs in children and young adults
Local cutaneous reaction + localized LAD
Treat with Azithromycin
LAD typically lasts 1-4 months
Disseminated, severe forms may
occur
Consider with FUO

Question 24

Having lymph nodes that are not non-mobile is a reassuring sign?

Answer 24

False bc it is fixed

Question 25

differential diagnosis: Generalized LAD

Answer 25

Generalized LAD usually indicates systemic and more serious causes.
HIV
Tuberculosis
Mononucleosis
Sarcoidosis
Systemic Lupus
Medication
Lymphomas
Other rare conditions

Question 26

Identify the common medications that can cause LAD

Answer 26

Penicillin, Atenolol, Captopril, Cephalosporins

Question 27

Appearance of lymph nodes w/malignancy

Answer 27

Hard fixed LAD: possibly matted, firm, rubbery

Question 28

More warning signs

Answer 28

Anytime generalized LAD is present
Anytime localized LAD persists > 3-4 weeks
Painless LAD
Most Healthy kids have palpable LAD up to 2 cm

Question 29

Generalized LAD Physical Exam

Answer 29

General inspection: diaphoresis, chills, overall appearance, body habitus,
BP, T, R, P, weight comparison and oximetry
Skin: Rash, change in color, texture, lesions, swelling, warmth
Eyes: infection or discharge
Ears: redness, lesions of the canal, TM
Nose: rhinorrhea, patency, polyps/masses
Oral exam: tonsils for redness, exudate, masses
Lungs: auscultation
Breast exam: masses, dimpling, retraction of nipple, d/c
Abdominal exam for organ enlargement, distention
Male/Female GU exam depending on CC

Question 30

Assessment for Generalized Lymphadenopathy

Answer 30

First: CBC, Chest Radiograph, HIV testing
Second: TB, Syphilis, ANA, Heterophile test
Finally: Biopsy of most abnormal node

Question 31

Lab Option for LAB

Answer 31

General Labs:
* CBC with differential
* Chemistry panel (Chem 12)
* Hepatitis panel
* ANA
Infectious disease testing
* Rapid strep test and culture
* Heterophile antibody test or EBV titers
* CMV titer
* RPR
* HIV
* PPD
* Blood cultures for septic workup
* STD cultures
* West Nile, Zika
* Borrelia burdorgeri (Lyme disease)
* Bartonella henselae IgG, IgM (Cat scratch)
* Francisella tularensis antibody (Tularemia)

Question 32

Imaging Studies

Answer 32

CXR (hilar/mediastinal LAD)
CT chest/abd/pelvis/neck
Ultrasound of node
PET scan
Diagnostic mammography
Lymphangiography
MRI
Gallium scans

Question 33

Surgical options to detect Generalized LAD

Answer 33

FNA (fine needle aspiration): doesn’t guarantee accurate
sample/dx
Excisional biopsy: diagnostic procedure of choice
Ideally, the largest, most suspicious, and most accessible node is chosen
Few complications (nerve/vascular
injury)
Axillary and inguinal nodes are
avoided
Preferred supraclavicular, cervical

Question 34

Lymphedema

Answer 34

Usually acquired secondary to trauma to ducts after surgery or metastasis due to obstruction of the system

Primary: Congenital abnormality of the lymphatics
Secondary: Usually following removal/ damage to lymph nodes
(trauma, irradiation, extensive malignancy)
Treatment
Exercise
Pneumatic compression or compression garments
Massage

Question 35

Lymphadenitis

Answer 35

Inflammation of lymph node(s) secondary to
drainage of bacteria or toxic substances into the nodes. Marked
edema, erythema, tenderness.
Treat with antibiotics, heat

Question 36

Cervial Lymphadenistis

Answer 36

Unilateral usually caused by S.aureus, GAS, or oral anaerobes
Erythema of the overlying skin
Depends on how sick the patient is
Watchful waiting through hospitalization
Moderate symptoms: 10-14 day course of antibiotic
Amoxicillin-Clavulanate
Cephalexin
Trimethoprim-sulfamethoxazole
Clindamycin

Question 37

Lymphangitis

Answer 37

Inflammation of lymphatic channel or vessels usually
secondary to strep; chills, and fever.
Treat with oral vs IV antibiotics and heat

infection spreads along the
lymphatic system
Complication of infected wounds,
abscess, or cellulitis
Group A Hemolytic Strep most
common
Can lead to sepsis, death