see also:

• splenomegaly

• the body has approximately 600 lymph nodes, but only those in the submandibular, axillary or inguinal regions may normally be palpable in healthy people
• in most patients, lymphadenopathy has a readily diagnosable infectious cause.
• when the cause of the lymphadenopathy remains unexplained, a 3-4 week observation period is appropriate when the clinical setting indicates a high probability of benign disease
• localized adenopathy should prompt a search for an adjacent precipitating lesion and an examination of other nodal areas to rule out generalized lymphadenopathy.
• nodes are generally considered to be normal if they are up to 1 cm in diameter; however, some authors suggest that epitrochlear nodes larger than 0.5 cm or inguinal nodes larger than 1.5 cm should be considered abnormal
• when a lymph node rapidly increases in size, its capsule stretches and causes pain.
• the presence or absence of tenderness does not reliably differentiate benign from malignant nodes
• stony-hard nodes are typically a sign of cancer, usually metastatic.
• very firm, rubbery nodes suggest lymphoma
• nodes that are matted can be either benign (e.g., tuberculosis, sarcoidosis or lymphogranuloma venereum) or malignant (e.g., metastatic carcinoma or lymphomas)
• only 1-2% of patients with unexplained lymphadenopathy presenting to a GP are found to have a malignancy causing it.¹⁾
• in primary care settings, patients 40 years of age and older with unexplained lymphadenopathy have about a 4 percent risk of cancer versus a 0.4 percent risk in patients younger than age 40.
• biopsy should be avoided in patients with probable viral illness because lymph node pathology in these patients may sometimes simulate lymphoma and lead to a false-positive diagnosis of malignancy.

• 4 key points in the history:
  • are there localizing symptoms or signs to suggest infection or neoplasm in a specific site?
  • are there constitutional symptoms such as fever, weight loss, fatigue or night sweats to suggest disorders such as tuberculosis, lymphoma, collagen vascular diseases, unrecognized infection or malignancy?
  • are there epidemiologic clues such as occupational exposures, recent travel or high-risk behaviors that suggest specific disorders?
  • is the patient taking a medication that may cause lymphadenopathy? (eg. phenytoin or serum-sickness)

• EBV / glandular fever / infectious mononucleosis
• HIV / AIDS
• secondary syphilis
• lymphoma
• advanced malignancy
• toxoplasmosis
• ticks in Australia
• serum sickness - eg. reactions to cephalosporins (esp. cefaclor), penicillins or sulphonamides
• other medications - phenytoin, carbamazepine, gold, allopurinol, atenolol, captopril, hydralazine, primidone, pyrimethamine, quinidine, sulindac
• rheumatoid arthritis
• systemic lupus erythematosus (SLE)
• sarcoidosis
• mastocytosis
• rubella - the hallmark of rubella in addition to the rash, is the generalized, tender lymphadenopathy that involves all nodes, but which is most striking in the suboccipital, postauricular, and anterior and posterior cervical nodes.
• Kikuchi disease - rare, mainly young women with Cx LNs and fevers, and rarely rubella-like rash or splenomegaly

• EBV / glandular fever / infectious mononucleosis
• lymphocytic leukaemia
• lymphoma
• sarcoidosis
• cat scratch disease
• Still's disease
• many other conditions

• generalised LN due to HIV
• Kaposi's sarcoma
• cytomegalovirus (CMV)
• toxoplasmosis
• tuberculosis (TB)
• cryptococcus
• syphilis
• lymphoma

• drains scalp and neck, skin of arms and pectorals, thorax, cervical and axillary nodes
• the presence of posterior Cx nodes helps differentiate EBV / glandular fever / infectious mononucleosis from streptococcal tonsillitis

• local infection eg. cradle cap, scalp infections
• EBV / glandular fever / infectious mononucleosis
• cytomegalovirus (CMV)
• rubella
• tuberculosis (TB)
• neoplasia / cancer / tumours - head and neck or lymphoma
• Kikuchi-Fujimoto disease
  • rare, benign, self-limiting, post-viral histiocytic necrotizing lymphadenitis mainly in those under 30yrs especially Asian ethinicities, mainly affecting the posterior cervical lymph nodes. It can also involve axillary and supraclavicular lymph nodes

• drains scalp and head

• local infection

• drains external auditory meatus, pinna, scalp

• local infection

• drains eyelids and conjunctivae, temporal region, pinna
• should not be confused with enlarged parotid gland as with mumps

• otitis externa

• viral keratoconjunctivitis
• measles
• cat scratch disease - Parinaud's syndrome with ocular involvement

• drains tongue, submaxillary gland, lips and mouth, conjunctivae

• infections of head, neck, sinuses, ears, eyes, scalp, pharynx
• neoplasia / cancer / tumours

• drains lower lip, floor of mouth, tip of tongue, skin of cheek

• EBV / glandular fever / infectious mononucleosis
• cytomegalovirus (CMV)
• toxoplasmosis

• drains tongue, tonsil, pinna, parotid
• may develop into suppurative cervical adenitis which need drainage (particularly young children)

• URTI /pharyngitis
• strept. tonsillitis
• EBV / glandular fever / infectious mononucleosis - look for posterior Cx nodes, splenomegaly, generalised LN's.
• Kawasaki disease - an acute febrile vasculitic syndrome of early childhood with usually a single, enlarged, nonsuppurative cervical node measuring approximately 1.5 cm and high fever, bilat. conjunctivitis, strawberry tongue, lip fissures, erythema and edema of the hands and feet, and other features.
• rubella

• supraclavicular nodes are the most worrisome for malignancy.
• the risk of malignancy is ~90% in patients > 40 years and 25% in those younger than age 40
• having the patient perform a Valsalva's maneuver during palpation of the supraclavicular fossae increases the chance of detecting a node
• right drains mediastinum, lungs, esophagus
• left (Virchow node) drains thorax, abdomen via thoracic duct thus may signal pathology in the testes, ovaries, kidneys, pancreas, prostate, stomach or gallbladder

• breast cancer
• lung cancer
• oesophageal cancer
• other malignancies
• Kikuchi-Fujimoto disease
  • rare, benign, self-limiting, post-viral histiocytic necrotizing lymphadenitis mainly in those under 30yrs especially Asian ethinicities, mainly affecting the posterior cervical lymph nodes. It can also involve axillary and supraclavicular lymph nodes

• mediastinal lymph nodes on CXR, often bilateral

• pneumonia including Mycoplasma
• lymphoma
• sarcoidosis
• lung cancer and mediastinal malignancies
• tuberculosis (TB)
• HIV / AIDS
• measles
• pneumoconiosis, silicosis, berylliosis
• extrinsic allergic alveolitis - eg. bird fancier's lung
• adult-onset Still's disease
• intestinal lipodystrophy (Whipple's disease)

• axillary drains arm, thoracic wall, breast
• epitrochlear drains ulnar aspect of forearm and hand

• local infections - cellulitis, ascending lymphangitis, skin abscess, tinea, etc
• post-vaccination - eg. mRNA Covid-19 vaccines often caused transient tender axillary LNs
• EBV / glandular fever / infectious mononucleosis
• cat scratch disease
• Australian tiger and brown snake bites
• spider bites in Australia
• breast cancer - axillary
• silicone breast implants - axillary
• melanoma - axillary
• lymphoma
• lung cancer - axillary
• tuberculosis (TB)
• brucellosis - axillary
• filariasis - axillary, inguinal, crural
• Kikuchi-Fujimoto disease
  • rare, benign, self-limiting, post-viral histiocytic necrotizing lymphadenitis mainly in those under 30yrs especially Asian ethinicities, mainly affecting the posterior cervical lymph nodes. It can also involve axillary and supraclavicular lymph nodes
• Systemic-Onset Juvenile Idiopathic Arthritis - axillary +/- splenomegaly
• sarcoidosis - epitrochlear
• secondary syphilis - epitrochlear
• tularaemia - epitrochlear

• drains penis, scrotum, vulva, vagina, perineum, gluteal region, lower abdominal wall, lower anal canal

• local infections - cellulitis, ascending lymphangitis, skin abscess, tinea, etc
• STD's - including lymphogranuloma venereum, chancroid, Herpes simplex virus (HSV), gonococcal, syphilis
• EBV / glandular fever / infectious mononucleosis
• cat scratch disease
• Australian tiger and brown snake bites
• skin cancer
• lymphoma
• pelvic malignancy
• bubonic plague
• filariasis - axillary, inguinal, crural

• Coccidioidomycosis - Arizona, southern California, New Mexico, western Texas
• Bubonic plague - Southwestern United States
• histoplasmosis - Southeastern or central United States
• scrub typhus - Southeast Asia, India, northern Australia
• African trypanosomiasis (sleeping sickness) - Central or west Africa
• American trypanosomiasis (Chagas' disease) - Central or South America
• Kala-azar (leishmaniasis) - East Africa, Mediterranean, China, Latin America
• typhoid_fever - Mexico, Peru, Chile, India, Pakistan, Egypt, Indonesia
• filariasis - axillary, inguinal, crural