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lymphadenopathy

lymphadenopathy

see also:

introduction

  • 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.

initial workup

  • 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)

generalised lymphadenopathy

DDx

with splenomegaly
with HIV

regional lymphadenopathy

posterior cervical lymphadenopathy

DDx

suboccipital lymphadenopathy

  • drains scalp and head

DDx

  • local infection

post-auricular lymphadenopathy

  • drains external auditory meatus, pinna, scalp

DDx

  • local infection

pre-auricular lymphadenopathy

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

DDx

  • otitis externa
oculoglandular syndromes

submandibular lymphadenopathy

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

DDx

submental lymphadenopathy

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

DDx

jugular (anterior cervical) lymphadenopathy

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

DDx

  • 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.

supraclavicular lymphadenopathy

  • 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

DDx

hilar lymphadenopathy

  • mediastinal lymph nodes on CXR, often bilateral

DDx

upper limb lymphadenopathy

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

DDx

inguinal or groin lymphadenopathy

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

DDx

  • 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
lymphadenopathy.txt · Last modified: 2011/08/04 04:12 by gary