Do we all have lymph nodes?
- Yes. # of lymph nodes in the body: ~ 600
Structure and function of lymph nodes:
- Lymph nodes are small, ovoid nodules normally ranging in size from a few millimeters to 2 cm.
- They are distributed in clusters along the course of lymphatic vessels located throughout the body.
- The primary function of lymph nodes is to filter out microorganisms and abnormal cells that have collected in lymph fluid.
- Node dimensions: In general, lymph nodes greater than 1 cm in diameter are considered to be abnormal. eg 1.7 cm x 1.8 cm x 2.2 cm ... before commencing antiobiotics (Amoxycillin + clavulanate)
- Lymphadenopathy refers to nodes that are abnormal in either size, consistency or number.
- Lymphadenitis is the inflammation or enlargement of a lymph node.
Careful palpation of the submandibular (bawah dagu), anterior and posterior cervical (leher), supraclavicular (pangkal leher), axillary (ketiak) and inguinal (celah kangkang) nodes can be accomplished in a short time and will identify patients with generalized lymphadenopathy.
A localised cervical lymphadenopathy is either on the right side or left side of the neck. It can be solitary or aggregated (like a bunch of grapes).
Characteristics:
- Location - Depends on underlying etiology
- Number - Single, local groupings (regional), or generalized (ie, multiple regions)
- Size/shape - Normal lymph nodes range in size from a few millimeters to 2 cm in diameter; enlarged nodes are greater than 2-3 cm with regular/irregular shapes
- Consistency - Soft, firm, rubbery, hard, fluctuant, warm
- Tenderness - Suggestive of an infectious process but does not rule out malignant causes
1. “Generalized lymphadenopathy” if lymph nodes are enlarged in two or more non contiguous areas (25%). eg Cytomegalovirus.
2. “Localized lymphadenopathy” if only one area is involved (75%):
- Head and neck (55%)
- Supraclavicular (1%)
- Axillary (5%)
- Inguinal (14%)
(i) Head and neck (55%)
Submandibular
- tongue
- submaxillary gland - dental caries/abscess
- lips and mouth
- conjunctivae
- lower lip
- floor of mouth
- tip of tongue
- skin of cheek
- tongue
- tonsil
- pinna
- parotid
- scalp and neck
- skin of arms and pectorals
- thorax
- cervical and axillary nodes
Suboccipital
- scalp and head
- external auditory meatus
- pinna
- scalp
- eyelids and conjunctivae
- temporal region
- pinna
Right supraclavicular node
- mediastinum; mediastinal - Epstein-Barr virus (EBV) (mononucleosis)
- lungs
- esophagus
- thorax
- abdomen
- via thoracic duct
Axillary
- arm
- thoracic wall
- breast
- ulnar aspect of forearm and hand
INVESTIGATIONS
- Skin test/Mantoux test - walk-in test done at Medical clinic (KPP). Uses 1 ml of tuberculin or purified protein derivative (PPD). To confirm the diagnosis of tuberculous lymphadenopathy; alternative is interferon-gamma release assays (IGRA). TRO TB; check for recent/past exposure to TB organism. Results are read on the 4th day: eg a 15 mm induration is considered "positive" or evidence of having antibodies/immunity to the TB organism or previous exposure - could be a recent house renovations with a coughing worker; could be a coughing husband, etc.
- Blood test: ESR, FBP. TRO bacterial/viral infection. Turnaround time (TAT) for blood results is 1 week from Hematology. CBC count - Elevated WBC count may indicate an infectious etiology. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) - Elevated ESR and CRP are nonspecific indicators of inflammation.
- Serology. Monospot or Epstein-Barr Virus (EBV) serologies. To confirm the diagnosis of infectious mononucleosis.
- CT Scan - location, size and # of abnormal lymph nodes involved; contents of lymph node - fluid/pus or cellular. Interpretations and Radiology reports are available by the 3rd day.
- CXR (chest x-ray) - Chest radiography may be helpful in determining pulmonary involvement or spread of lymphadenopathy to the chest. TRO pulmonary TB (PTB). Films are available online the same day. Radiology report is made available online.
- Ultrasound. Ultrasonography may be useful for verifying lymph node involvement and taking accurate measurements of enlarged nodes. Ultrasound is not able to differentiate between benign and malignant forms of lymphadenopathy.
- Node biopsy: FNAC versus excisional biopsy ... performed under local anaesthesia ... procedure does not need fasting; performed after 1 week course of antibiotics (Amoxycillin + calvulanate). Drainage if filled with pus or fluid. Aspirates, if any.
- Gram stain of aspirated tissue. To evaluate bacterial etiologies.
- Culture and Sensitivity (C&S). Culture of aspirated tissue or biopsy specimen. To determine the causative organism and its sensitivity to antibiotics.
- Liver function tests (LFT). May indicate hepatic or systemic involvement; elevated transaminase levels can be seen in infectious mononucleosis.
CAUSES
In most cases, a careful history and physical examination will identify a readily diagnosable cause of the lymphadenopathy. Refer to the algorithm for investigating lymphadenopathy. The causes are categorized into 3 types:
Diagnostic causes:
- upper respiratory tract infection (URTI),
- pharyngitis (sakit tekak),
- periodontal disease (penyakit gigi dan gusi),
- conjunctivitis (sakit mata),
- lymphadenitis (radang noda limfa),
- tinea (kulat),
- insect bites (gigitan serangga),
- recent immunization (imunisasi terhampir),
- cat-scratch disease (cakar kucing)
- dermatitis (radang kulit)
- mononucleosis
- syphilis
- lymphoma
- HIV
- if generalised - review epidemiologic clues. Patients with generalized lymphadenopathy will need further diagnostic evaluation that often includes biopsy.
- if localized - review history, regional examination and epidemiologic clues. Patients with localized lymphadenopathy + a worrisome clinical picture will need further diagnostic evaluation that often includes biopsy.
- Bartonella henselae (catscratch disease) – Single-node involvement determined by scratch site; discrete, mobile, nontender
- Coccidioides immitis (coccidioidomycosis) – Mediastinal
- Cytomegalovirus – Generalized
- Epstein-Barr Virus (EBV) (mononucleosis) - Anterior cervical, mediastinal, bilateral; discrete, firm, nontender
- Francisella tularensis (tularemia) - Cervical, mediastinal, or generalized; tender
- Histoplasma capsulatum (histoplasmosis) – Mediastinal
- Atypical Mycobacterium - Cervical, submandibular, submental (usually unilateral); most commonly in immunocompetent children aged 1-5 years
- Mycobacterium tuberculosis - Mediastinal, mesenteric, anterior cervical, localized disease (discrete, firm, mobile, tender); generalized hematogenous spread (soft, fluctuant, matted, and adhere to overlying, erythematous skin)
- Parvovirus - Posterior auricular, posterior cervical, occipital
- Rubella - Posterior auricular, posterior cervical, occipital
- Salmonella – Generalized
- Seborrheic dermatitis, scalp infections - Occipital, postauricular
- Staphylococcus aureus adenitis - Cervical, submandibular; unilateral, firm, tender
- Group A streptococcal (GAS) pharyngitis - Submandibular and anterior cervical; unilateral, firm, tender
- Toxoplasma gondii - Generalized, often nontender
- Viral pharyngitis - Bilateral postcervical; firm, tender
- Yersinia enterocolitica - Cervical or abdominal
- Yersinia pestis (plague) - Axillary, inguinal, femoral, cervical; extremely tender with overlying erythema
- Juvenile rheumatoid arthritis
- Graft versus host disease
- Acute lymphoblastic leukemia
- Lymphosarcoma
- Reticulum cell sarcoma
- Non-Hodgkin lymphoma
- Malignant histocytosis or histocytic lymphoma
- Nonendemic Burkitt tumor
- Nasopharyngeal rhabdomyosarcoma
- Neuroblastoma
- Thyroid carcinoma, chronic lymphocytic thyroiditis
- Histiocytosis X
- Kikuchi disease
- Benign sinus histiocytosis
- Angioimmunoblastic or immunoblastic lymphadenopathy
- Chronic pseudolymphomatous lymphadenopathy (chronic benign lymphadenopathy)
- Chronic granulomatous disease of childhood
- Acquired immunodeficiency syndrome
- Hyperimmunoglobulin E (Job) syndrome
- Gaucher disease
- Niemann-Pick disease
- Cystinosis
- Sickle cell anemia
- Thalassemia
- Congenital hemolytic anemia
- Autoimmune hemolytic anemia
- Kawasaki disease
- PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and adenitis) syndrome
- Sarcoidosis
- Castleman disease (also known as benign giant lymph node hyperplasia)
- Mesantoin – most commonly causes cervical lymphadenitis
- Hydantoin - Generalized lymphadenopathy
REGIONAL LYMPHADENITIS
In a patient with regional lymphadenitis, knowledge of lymphatic drainage patterns and pathologic processes most likely to affect these areas can facilitate diagnostic investigation.
Cervical lymph nodes
Cervical lymph nodes receive lymphatic drainage from the head, neck, and oropharyngeal cavities.
Infections associated with cervical lymph nodes are as follows:
- Skin and soft tissue infections of the face
- Dental abscesses
- Otitis externa
- Bacterial pharyngitis
- Cytomegalovirus
- Adenovirus infection
- Rubella
- Toxoplasmosis
- Hodgkin lymphoma
- Non-Hodgkin lymphomas
- Squamous cell carcinomas of nasopharyngeal or laryngeal structures
BIOPSY
Choice of biopsy: FNAC versus Excisional biopsy
Fine-needle aspiration and cytology (FNAC) is an alternative to excisional biopsy.
Advantages of excisional biopsy:
- larger tissue mass to examine
- can examine the entire abnormal lymph node
- FNAC often yields a high number of non diagnostic results,
- because of the small amount of tissue obtained and
- the inability to examine the architecture of the lymph node.
- There may be some risk of sinus tract formation, depending on the underlying pathology.
Pathology reports should be available within a week of performing FNAC or excisional biopsy.
Incision and drainage is the treatment for lymphadenitis with abscess formation.
For atypical mycobacterial lymphadenitis, neither incision and drainage nor FNA should be performed as either of these may increase the risk of fistula formation and drainage.
CANCEROUS OR NOT?
Is it cancer or not? Is it benign or malignant?
Physical examination findings suggestive of malignancy are as follows:
- Firm
- Hard
- Fixed
- Non tender
- Soft
- Fluctuant
- Tender
- Overlying erythema or streaking
External links:
Lymphadenopathy
http://emedicine.medscape.com/article/956340-overview
http://www.aafp.org/afp/1998/1015/p1313.html
http://www.msdmanuals.com/professional/cardiovascular-disorders/lymphatic-disorders/lymphadenopathy
https://en.wikipedia.org/wiki/Lymphadenopathy
Lymphadenitis
http://emedicine.medscape.com/article/960858-overview
