eMedicine Specialties > Pediatrics: General Medicine > Hematology

Lymphadenopathy

Author: Vikramjit S Kanwar, MD, MBA, MRCP(UK), FAAP, Associate Professor of Pediatric Hematology and Oncology, Department of Pediatrics, Albany Medical Center; Faculty, Alden March Bioethics Institute
Coauthor(s): Richard H Sills, MD, Professor of Pediatrics, Upstate Medical University
Contributor Information and Disclosures

Updated: May 12, 2009

Introduction

Background

Lymph nodes, in conjunction with the spleen, tonsils, adenoids, and Peyer patches, are highly organized centers of immune cells that filter antigen from the extracellular fluid. Directly interior to the fibrous capsule is the subcapsular sinus. This allows lymph, an ultrafiltrate of blood, to traverse from the afferent lymph vessels, through the sinuses, and out the efferent vessels. The sinuses are studded with macrophages, which remove 99% of all delivered antigens.

Interior to the subcapsular sinus is the cortex, which contains primary follicles, secondary follicles, and the interfollicular zone. Follicles within the cortex are major sites of B-cell proliferation, whereas the interfollicular zone is the site of antigen-dependent T-cell differentiation and proliferation. The deepest structure within the lymph node is the medulla, consisting of cords of plasma cells and small B lymphocytes that facilitate immunoglobulin secretion into the exiting lymph.

The lymph node, with its high concentration of lymphocytes and antigen-presenting cells, is an ideal organ for receiving antigens that gain access through the skin or gastrointestinal tract. Nodes have considerable capacity for growth and change. Lymph node size depends on the person's age, the location of the lymph node in the body, and antecedent immunological events. In neonates, lymph nodes are barely perceptible, but a progressive increase in total lymph node mass is observed until later childhood. Lymph node atrophy begins during adolescence and continues through later life.

Pathophysiology

Most lymphadenopathy in children is due to benign self-limited disease such as viral infections, and adenopathy is secondary to an increase in normal lymphocytes and macrophages in response to an antigen. Other less common mechanisms responsible for adenopathy include nodal accumulation of inflammatory cells in response to an infection in the node (lymphadenitis), neoplastic lymphocytes or macrophages (lymphoma), or metabolite-laden macrophages in storage diseases (Gaucher disease).

Frequency

United States

The precise incidence of lymphadenopathy is not known, but estimates of palpable adenopathy in childhood vary from 38-45%,¹ and lymphadenopathy is one of the most common clinical problems encountered in pediatrics. Determining whether adenopathy is simply a normal response to frequent viral infections within an age group or if it is significant enough to consider more serious underlying disease is often difficult.

In the United States, common viral and bacterial infections are overwhelmingly the most common cause of adenopathy. Infectious mononucleosis and cytomegalovirus (CMV) are important etiologies, but adenopathy is usually caused by common viral upper respiratory tract infections. Localized lymphadenitis is most often caused by staphylococci and beta-hemolytic streptococci.

Other infections, such as human immunodeficiency virus (HIV), malignancies, and autoimmune diseases, are less common causes of adenopathy.

International

Infections that are rarely observed in the United States, such as tuberculosis, typhoid fever, leishmaniasis, trypanosomiasis, schistosomiasis, filariasis, and fungal infections, are common causes of lymphadenopathy in developing nations.² HIV infections must be strongly considered in areas of high incidence.

Mortality/Morbidity

In the United States, mortality and serious morbidity caused by adenopathy are unusual given the common infectious etiologies.

• Malignancies, such as leukemia, lymphomas, and neuroblastoma, are the primary causes of mortality in the United States.
• Significant morbidity and mortality are also associated with autoimmune disorders (eg, juvenile rheumatoid arthritis, systemic lupus erythematosus), histiocytoses, and storage diseases.
• HIV is an uncommon cause of adenopathy in the United States, but its associated mortality requires consideration.

Race

Race is not a factor in most lymphadenopathy. Rare causes may be associated with particular ethnic groups (eg, sarcoidosis in Africans, Kikuchi-Fujimori disease in Asians).

Sex

Sex does not influence childhood lymphadenopathy.

Age

Adenopathy is most common in young children whose immune systems are responding to newly encountered infections. Adenopathy may be seen in one third of neonates and infants, usually in nodes that drain areas with mild skin irritation. Generalized adenopathy is rare in the neonate and suggests congenital infections, such as CMV. Adenopathy related to malignancy is rare at all ages. If diagnosed, it is often secondary to leukemia or neuroblastoma in younger children, and to Hodgkin lymphoma in adolescents.

Clinical

History

• The differential diagnosis of lymphadenopathy is broad. A patient's medical history and review of systems is important in narrowing this differential. Upon examination, recognizing the pattern of lymph drainage aids in seeking an infectious focus.
• Although the underlying etiology is often self-limited infection, more serious underlying etiologies must be quickly recognized. Serious infections and malignancies are important considerations, as discussed in Outline - Etiologies of Lymphadenopathy.
• In adolescents, screening for intravenous drug use and sexual activity is important.

Physical

• Assess the size, location, and character of the adenopathy, along with any associated physical findings. Erythema, tenderness, warmth, and fluctuance suggests lymphadenitis, and nodes that are matted together, firm, and nontender suggest malignancy, although this distinction is not invariable.
• Recognize that most children have palpable lymph nodes in the anterior cervical, inguinal, and axillary regions that, if evaluated by adult standards, would qualify as lymphadenopathy. Lymphoid mass steadily increases after birth until age 8-12 years, and undergoes progressive atrophy during puberty.
• In young children, anterior cervical lymph nodes as large as 2 cm, axillary nodes as large as 1 cm, and inguinal nodes as large as 1.5 cm in diameter are normal, and further evaluation is usually not indicated. In a series of 457 children, malignancy was usually associated with nodes larger than 3 cm in diameter.³ However, the presence of even shotty (<0.5 cm) supraclavicular or epitrochlear adenopathy may be associated with malignancy and warrants further evaluation. Newborns usually have small adenopathy (<0.5 cm), and larger nodes not associated with a focus of inflammation are an indication for further evaluation.
• Seek a focus of infection or inflammation in the territory drained by the lymph nodes. For example, the classic manifestation of group A streptococcal pharyngitis is sore throat, fever, and anterior cervical lymphadenopathy (tonsillar node). When examining the oropharynx, pay special attention to the dentition. Similarly, impetigo of the buttock area is associated with inguinal adenopathy. Scalp lesions, such as seborrheic dermatitis (cradle cap), can cause newborn occipital adenopathy.
• Consider the possibility that palpable "lymph nodes" may in fact be other masses; for example, branchial cysts and other benign tumors can mimic cervical adenopathy.⁴   
• A careful history and physical examination, with a consideration of the factors listed above, help determine whether an enlarged lymph node merits further investigation.

Causes

Generalized lymphadenopathy is defined as enlargement of more than 2 noncontiguous lymph node groups. A thorough history and physical examination are critical in establishing a diagnosis. Causes of generalized lymphadenopathy include infections, autoimmune diseases, malignancies, histiocytoses, storage diseases, benign hyperplasia, and drug reactions.

• Infections
  • Generalized lymphadenopathy is most often associated with systemic viral infections.
  • Infectious mononucleosis results in widespread adenopathy.
  • Roseola infantum (caused by human herpes virus 6), cytomegalovirus (CMV), varicella, and adenovirus all cause generalized lymphadenopathy.
  • Human immunodeficiency virus (HIV) is often associated with generalized adenopathy, which may be the presenting sign. Children with HIV are at increased risk for tuberculosis, as well.⁵
  • Although usually associated with localized node enlargement, some bacterial infections present with generalized adenopathy. Examples include typhoid fever caused by Salmonella typhi, syphilis, plague, and tuberculosis. Less common bacteremias, including those caused by endocarditis, result in generalized lymphadenopathies.
• Malignant etiologies
  • Concern about malignant etiologies often drives further diagnostic testing in children with adenopathy. Malignancy is often associated with constitutional signs, such as fever, anorexia, nonspecific aches and pains, weight loss, and night sweats. The acute leukemias and lymphomas often present with these nonspecific findings.
  • Generalized lymphadenopathy is present at diagnosis in two thirds of children with acute lymphoblastic leukemia (ALL) and in one third of children with acute myeloblastic leukemia (AML). Abnormalities of peripheral blood counts usually lead to the correct diagnosis. The lymphomas more often present with regional lymphadenopathy, but generalized lymphadenopathy occurs.
  • Constitutional signs and symptoms observed in the leukemias are less reliable findings in the lymphomas. Only one third of children with Hodgkin disease and 10% with non-Hodgkin lymphoma display them. Malignancies usually present with nodes that tend to be firmer and less mobile or matted; however, this finding can be misleading. Benign reactive lymph nodes may be associated with fibrotic reactions that make them firm.
• Storage diseases: Generalized lymphadenopathy is an important manifestation of the lipid storage diseases. In Niemann-Pick disease, sphingomyelin and other lipids accumulate in the spleen, liver, lymph nodes, and CNS. In Gaucher disease, the accumulation of the glucosylceramide leads to the engorgement of the spleen, lymph nodes, and the bone marrow. Although widespread lymphadenopathy is common, additional findings, such as hepatosplenomegaly and developmental delay in Niemann-Pick disease and blood dyscrasias in Gaucher disease, are usually present. These diagnoses are established by leukocyte assay.
• Drug reactions: Adverse drug reactions can cause generalized lymphadenopathy. Within a couple of weeks of initiating phenytoin, some patients experience a syndrome of regional or generalized lymph node enlargement, followed by a severe maculopapular rash, fever, hepatosplenomegaly, jaundice, and anemia. These symptoms abate 2-3 months after discontinuation of the drug. Several other drugs are implicated in similar symptomatology, including mephenytoin, pyrimethamine, phenylbutazone, allopurinol, and isoniazid.
• Other nonneoplastic etiologies: Rare nonneoplastic causes of generalized lymphadenopathy include Langerhans cell histiocytosis and Epstein-Barr virus (EBV)-associated lymphoproliferative disease. Autoimmune etiologies include juvenile rheumatoid arthritis, which often presents with adenopathy, especially during the acute phases of the disease. Sarcoidosis and graft verses host disease also merit consideration.

Regional lymphadenopathy involves enlargement of a single node or multiple contiguous nodal regions. Lymph nodes are clustered in groups throughout the body and are concentrated in the head and neck, axillae, mediastinum, abdomen, and along the vascular trunks of the extremities. Each group drains lymph from a particular region of the body. Knowledge of the pattern of lymph drainage aids in determining the etiology.

• Cervical lymphadenopathy: Cervical lymphadenopathy is a common problem in children.⁶ Cervical nodes drain the tongue, external ear, parotid gland, and deeper structures of the neck, including the larynx, thyroid, and trachea. Inflammation or direct infection of these areas causes subsequent engorgement and hyperplasia of their respective node groups. Adenopathy is most common in cervical nodes in children and is usually related to infectious etiologies. Lymphadenopathy posterior to the sternocleidomastoid is typically a more ominous finding, with a higher risk of serious underlying disease.
  • Infectious etiologies
    • Cervical adenopathy is a common feature of many viral infections. Infectious mononucleosis often manifests with posterior and anterior cervical adenopathy. Firm tender nodes that are not warm or erythematous characterize this lymph node enlargement. Other viral causes of cervical lymphadenopathy include adenovirus, herpesvirus, coxsackievirus, and CMV. In herpes gingivostomatitis, impressive submandibular and submental adenopathy reflects the amount of oral involvement.
    • Bacterial infections cause cervical adenopathy by causing the draining nodes to respond to local infection or by the infection localizing within the node itself as a lymphadenitis. Bacterial infection often results in enlarged lymph nodes that are warm, erythematous, and tender. Localized cervical lymphadenitis typically begins as enlarged, tender, and then fluctuant nodes. The appropriate management of a suppurative lymph node includes both antibiotics and incision and drainage. Antibiotic therapy should always include coverage for Staphylococcus aureus and Streptococcus pyogenes.
    • In patients with cervical adenopathy, determine whether the patient has had recent or ongoing sore throat or ear pain. Examine the oropharynx, paying special attention to the posterior pharynx and the dentition. The classic manifestation of group A streptococcal pharyngitis is sore throat, fever, and anterior cervical lymphadenopathy. Other streptococcal infections causing cervical adenopathy include otitis media, impetigo, and cellulitis.
    • Atypical mycobacteria cause subacute cervical lymphadenitis, with nodes that are large and indurated but not tender. The only definitive cure is removal of the infected node.⁷
    • Mycobacterium tuberculosis may manifest with a suppurative lymph node identical to that of atypical mycobacterium. Intradermal skin testing may be equivocal. A biopsy may be necessary to establish the diagnosis.
    • Catscratch disease, caused by Bartonella henselae, presents with subacute lymphadenopathy often in the cervical region. The disease develops after the infected pet (usually a kitten) inoculates the host, usually through a scratch. Approximately 30 days later, fever, headache, and malaise develop, along with adenopathy that is often tender. Several lymph node chains may be involved. Suppurative adenopathy occurs in 10-35% of patients. Antibiotic therapy has not been shown to shorten the course.
  • Noninfectious etiologies
    • Malignant childhood tumors develop in the head and neck region in one quarter of cases. In the first 6 years of life, neuroblastoma, leukemia, non-Hodgkin lymphoma, and rhabdomyosarcoma (in order of decreasing frequency) are most common in the head and neck region. In children older than 6 years, Hodgkin disease and non-Hodgkin lymphoma both predominate. Children with Hodgkin disease present with cervical adenopathy in 80-90% of cases as opposed to 40% of those with non-Hodgkin lymphoma.
    • Kawasaki disease is an important cause of cervical adenopathy. These children have fever for at least 5 days, and cervical lymphadenopathy is one of the 5 diagnostic criteria (of which 4 are necessary to establish the diagnosis).
• Submaxillary and submental lymphadenopathy: These nodes drain the teeth, tongue, gums, and buccal mucosa. Their enlargement is usually the result of localized infection, such as pharyngitis, herpetic gingivostomatitis, and dental abscess.
• Occipital lymphadenopathy: Occipital nodes drain the posterior scalp. These nodes are palpable in 5% of healthy children. Common etiologies of occipital lymphadenopathy include tinea capitis, seborrheic dermatitis, insect bites, orbital cellulitis, and pediculosis. Viral etiologies include rubella and roseola infantum. Rarely, occipital lymphadenopathy may be noted after enucleation of the eye for retinoblastoma.
• Preauricular lymphadenopathy: Preauricular nodes drain the conjunctivae, skin of the cheek, eyelids, and temporal region of the scalp and rarely are palpable in healthy children. The oculoglandular syndrome consists of severe conjunctivitis, corneal ulceration, eyelid edema, and ipsilateral preauricular lymphadenopathy. Chlamydia trachomatis and adenovirus can cause this syndrome.
• Mediastinal lymphadenopathy
  • Mediastinal nodes drain the thoracic viscera, including the lungs, heart, thymus, and thoracic esophagus. Because these nodes are not directly demonstrable upon physical examination, their enlargement must be indirectly assessed. Supraclavicular adenopathy is often associated with mediastinal adenopathy. Mediastinal nodes may cause cough, wheezing, dysphagia, airway erosion with hemoptysis, atelectasis, and the obstruction of the great vessels, which constitutes superior vena cava syndrome. Airway compromise may be life threatening.
  • Mediastinal lymphadenopathy is usually a sign of serious underlying disease. More than 95% of mediastinal masses are caused by tumors or cysts. Lymphomas and acute lymphoblastic leukemia are the most common etiologies and usually involve the anterior mediastinum. These malignancies are associated with a high risk of superior vena cava syndrome and are associated with several potentially life-threatening complications, as follows:
    • The danger of sedation of patients, especially in the supine position for scans and procedures (The prone position actually may be safer.)
    • The risk during intubation of these patients, usually at the time of biopsy or placement of a central venous catheter
    • The risk of cardiovascular collapse during general anesthesia because of compression of venous return or because of previously undiagnosed pleural effusions
    • The risk of losing the ability to establish a pathologic diagnosis because of the use of steroids or radiation therapy
  • Unlike most other adenopathies, mediastinal lymphadenopathy is less frequently a result of infection. Infections frequently involve the hilar region and include histoplasmosis, coccidioidomycosis, and tuberculosis.
  • Nonlymphoid mediastinal tumors may be confused with adenopathy. These include neurogenic tumors (usually found in the posterior mediastinum), germ cell tumors, and teratomas.
  • Nonneoplastic conditions may also be confused with mediastinal adenopathy. These include the typically large thymus of a child, substernal thyroid glands, bronchogenic cysts, and abnormalities of the great vessels.
• Supraclavicular lymphadenopathy
  • Supraclavicular nodes drain the head, neck, arms, superficial thorax, lungs, mediastinum, and abdomen. Left supraclavicular nodes also reflect intra-abdominal drainage and enlarge in response to malignancies in that region. This is particularly true when adenopathy in this region occurs in the absence of other cervical adenopathy.
  • Right supraclavicular nodes drain the lung and mediastinum and are typically enlarged with intrathoracic lesions.
  • Serious underlying disease is frequent in children with supraclavicular adenopathy and always merits further evaluation. The potential for malignancy necessitates peripheral blood counts, skin testing for tuberculosis, and chemical studies, including uric acid, lactate dehydrogenase, calcium (Ca), phosphorus (P), and renal and hepatic function studies. Chest radiography and possibly CT scanning are indicated.
  • Several important infections may occur with supraclavicular adenopathy, including tuberculosis, histoplasmosis, and coccidioidomycosis.
  • Early lymph node biopsy should be considered in children with supraclavicular adenopathy.
• Axillary lymphadenopathy
  • Axillary nodes drain the hand, arm, lateral chest, abdominal walls, and the lateral portion of the breast.
  • A common cause of axillary lymphadenopathy is catscratch disease. Local axillary skin infection and irritation commonly are associated with local adenopathy. Other etiologies include recent immunizations in the arm (particularly with bacille Calmette-Guerin vaccine), brucellosis, juvenile rheumatoid arthritis, and non-Hodgkin lymphoma.
  • Hidradenitis suppurativa is a condition of enlarged tender lymph nodes that typically affects children with obesity and is caused by recurrent abscesses of lymph nodes in the axillary chain. The etiology is unknown, and treatment may include antibiotics. Many patients require incision and drainage.
• Abdominal lymphadenopathy
  • Abdominal nodes drain the lower extremities, pelvis, and abdominal organs. Although abdominal adenopathy is not usually demonstrable upon physical examination, abdominal pain, backache, increased urinary frequency, constipation, and intestinal obstruction secondary to intussusception are possible presentations.
  • Mesenteric adenitis is thought to be viral in etiology and is characterized by right lower quadrant abdominal pain caused by nodal enlargement near the ileocecal valve. Differentiating mesenteric adenitis from appendicitis may be difficult.
  • Mesenteric adenopathy may be caused by non-Hodgkin lymphoma or Hodgkin disease.
  • Typhoid fever and ulcerative colitis are other etiologies of mesenteric adenopathy.
• Iliac and inguinal lymphadenopathy: The lower extremities, perineum, buttocks, genitalia, and lower abdominal wall drain to these nodes. They are typically palpable in healthy children, although they are usually no larger than 1-1.5 cm in diameter. Regional lymphadenopathy is typically caused by infection; however, insect bites and diaper dermatitis are also frequent. Nonlymphoid masses that may be confused with adenopathy include hernias, ectopic testes, and lipomas.

Outline - Etiologies of Lymphadenopathy

I. Generalized lymphadenopathy

1. Infections
   1. Viral
      • Common upper respiratory infections
      • Infectious mononucleosis
      • CMV
      • Acquired immunodeficiency syndrome
      • Rubella
      • Varicella
      • Measles
   2. Bacterial
      • Septicemia
      • Typhoid fever
      • Tuberculosis
      • Syphilis
      • Plague
   3. Protozoal - Toxoplasmosis
   4. Fungal - Coccidioidomycosis
2. Autoimmune disorders and hypersensitivity states
   1. Juvenile rheumatoid arthritis
   2. Systemic lupus erythematosus
   3. Drug reactions (eg, phenytoin, allopurinol)
   4. Serum sickness
3. Storage Diseases
   1. Gaucher disease
   2. Niemann-Pick disease
4. Neoplastic and proliferative disorders
   1. Acute leukemias
   2. Lymphomas (Hodgkin, non-Hodgkin)
   3. Neuroblastoma
   4. Histiocytoses

II. Regional lymphadenopathy

1. Cervical
   1. Viral upper respiratory infection
   2. Infectious mononucleosis
   3. Rubella
   4. Catscratch disease
   5. Streptococcal pharyngitis
   6. Acute bacterial lymphadenitis
   7. Toxoplasmosis
   8. Tuberculosis/atypical mycobacterial infection
   9. Acute leukemia
   10. Lymphoma
   11. Neuroblastoma
   12. Rhabdomyosarcoma
   13. Kawasaki disease
2. Submaxillary and submental
   1. Oral and dental infections
   2. Acute lymphadenitis
3. Occipital
   1. Pediculosis capitis
   2. Tinea capitis
   3. Secondary to local skin infection
   4. Rubella
   5. Roseola
4. Preauricular
   1. Local skin infection
   2. Chronic ophthalmic infection
   3. Catscratch disease
5. Mediastinal
   1. Acute lymphoblastic leukemia
   2. Lymphoma
   3. Sarcoidosis
   4. Cystic fibrosis
   5. Tuberculosis
   6. Histoplasmosis
   7. Coccidioidomycosis
6. Supraclavicular
   1. Lymphoma
   2. Tuberculosis
   3. Histoplasmosis
   4. Coccidioidomycosis
7. Axillary
   1. Local infection
   2. Catscratch disease
   3. Brucellosis
   4. Reactions to immunizations
   5. Lymphoma
   6. Juvenile rheumatoid arthritis
8. Abdominal
   1. Acute mesenteric adenitis
   2. Lymphoma
9. Inguinal
   1. Local infection
   2. Diaper dermatitis
   3. Insect bites
   4. Syphilis
   5. Lymphogranuloma venereum

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