Diagnosis

Lymphadenopathy

Etiology

Cause [ne6][dtq][nuo][wte]

1. Infectious

   • Viral:

     • Acute: Rhinovirus, adenovirus, influenza, parainfluenza, respiratory syncytial virus, herpes simplex virus, measles, mumps, rubella, varicella

     • Subacute or chronic: EBV, CMV, HIV

   • Bacterial:

     • Acute: Staphylococcus aureus, group A streptococcus, anaerobic

     • Subacute or chronic: Bartonella, Salmonella,  Syphilis, and Yersinia

     • Neonates: Group B streptococcus

   • Zoonosis: Bartonella henselae (Cat scratch disease), Toxoplasmosis, Tularemia, Brucellosis, Histoplasmosis, Trypanosomiasis

   • Mycobacterium tuberculosis and atypical mycobacterial

   • Fungal

   • Parasites: toxoplasmosis, Chagas

2. Malignancies

   • Lymphoma

   • Leukemia

   • Rhabdosarcoma

   • Neuroblastoma

   • Metastasis (lung, GI, breast, kidney, nasopharyngeal and thyroid cancer)

3. Autoimmune disease

   • Sarcoidosis

   • Rheumatoid arthritis

   • Serum sickness

   • Systemic lupus erythematosus

4. Inborn metabolic storage disorder

   • Niemann-Pick disease

   • Gaucher disease

5. Exposure to toxic/medication

   • Allopurinol, atenolol, captopril, carbamazepine, cephalosporins, gold, hydralazine, penicillin, phenytoin, primidone, para methylamine, quinidine, sulfonamides, and sulindac

6. Congenital neck mass

   • Thyroglossal duct cyst

   • Dermoid

   • Branchial cleft

   • Lymphovascular malformation

   • Hemangioma

   • Ectopic thymus

7. Miscellaneous

   • Kikuchi-Fujimoto disease

   • Rosai-Dorfman disease

   • Langerhans cell histiocytosis

   • Kawasaki disease

   • Castleman disease

Pathophysiology [wte]

1. Lymphatic fluid represents the body's afferent extracellular (interstitial) fluid

2. Lymphatic channels conduct this fluid and label antigens with antigen-presenting cells

3. The lymphatic channels converge regionally to form discreet lymph nodes

4. The lymph node functions as an antigen filter and exposes B-cell lymphocytes, T-cell lymphocytes, and macrophages to the interstitial antigens (immune surveillance)

5. In case of a immune response, there is multiplication of the responding resistant cell line; thus, the node increases in size

6. Cell lines can commonly multiply by 3 to 5 times in 6 to 24 hours

Epidemiology

Incidence per 100.000 [fnd][sbh][b4c][ne6]

Approach

• Lymph node assessment: [wte]

  1. Age:

     • Neonates: congenital infection (CMV or Toxoplasma gondii)

     • 3-5 years old: Upper respiratory tract infections, pharyngitis, otitis, or conjunctivitis

     • Adolescents: Sexually transmitted disease

  2. Duration:

     • Acute enlargement --> acute viral or bacterial infection

     • Chronic lymphadenopathy lasts more than 4–6 weeks --> medications (phenytoin, isoniazid, pyrimethamine), malignancy, immunologic disorders, or Kawasaki disease

  3. Location: May reflects the lymphatic drainage of their location

     • Unilateral suggest bacterial infections

     • Bilateral suggest viral infections (influenza, adenovirus)

     • Generalized: EBV, CMV, HIV, lymphoma

     • Anatomic: Submandibular, submental, jugular, cervical, pectoral, suboccipital, postauricular, supraclavicular, axillar, epitrochlear, inguinal

  4. Size: Pathological size vary depending on age and location (rough estimate > 1cm)

  5. Overlying skin changes (discolouration, induration)

  6. Pain: Tender (infection) or non-tender (rule out malignancy)

  7. Consistency: soft (infection/inflammation), rubber (may suggest malignancy)

  8. Clustered may indicate malignancy

  9. Fixed or mobile

  10. Surface: smooth or irregular

  11. Recent infections: tooth, mouth ulcer, cough, impetigo, cellulitis, sexually transmitted disease

  12. History of foreign travel

  13. Exposure to animals or insect bites

  14. Consumption of under-cooked food/untreated water

  15. Recent immunizations

  16. Medications

  17. Red flags: Weight loss, night sweats, long-lasting fever, easy bruising, joint pain/swelling, rash

• Blood test: blood cell count, WBC, CRP, sedimentation rate, liver enzymes, lactate dehydrogenase, uric acid

• Monospot: Streptococcus pyogenes antigens

• Induced sputum

• Serelogy: EBV, HIV, CMV, Parvovirus B 19, Bartonella spp., Brucella spp., Toxoplasma gondii, tuberculosis (IGRA), syphilis, Herpes simplex virus, Hepatitis B

• Blood smear

• Chest x-ray: mediastinal widening or lymph node due to lymphoma and sarcoidosis

• Ultrasonography: size and monitoring

• CT collum

• Fine-needle aspiration

• Biopsy - The gold standard for diagnosis of lymphadenopathy

• CT abdomen

• MRI

Treatment

Treat the underlying condition [wte]

1. Treatment of the neoplasm

2. Bacterial disease: Supportive care, antibiotics, and elimination of nidus of infection

3. Viral disease: Observation and supportive care or treatment of the virus if possible

4. Toxin or medication exposure: Removal of offending medication/toxin if possible

Differential diagnoses

Acute sinusitis, Branchial cleft cyst, Breast cancer, Brucellosis, Cat scratch disease, Cellulitis, Coxsackievirus infection, Cytomegalovirus, Dental infection, Dermoid Cyst, Drug side effects, Fungal infection, Hemangioma, Herpes simplex, Histoplasmosis, HIV, Influenza, Kawasaki disease, Leukemia, Lymphoma, Malignant melanoma, Mononucleosis, Neuroblastoma, Parotitis, Pharyngitis, Rhabdomyosarcoma, Rheumatoid arthritis, Sarcoidosis, Sjogren syndrome, Squamous cell carcinoma, Syphilis, Systemic lupus erythematosus, Thyroglossal duct cyst, Thyroid cancer, Toxoplasmosis, Tuberculosis, Tularemia, Typhoid fever