Lymphadenopathy overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Raviteja Guddeti, M.B.B.S. [2]
Overview
Lymphadenopathy (also known as "enlarged lymph nodes") refers to lymph nodes which are abnormal in size, number or consistency. Common causes of lymphadenopathy are infection, autoimmune disease, or malignancy. Lymphadenopathy may be classified according to distribution into 2 groups: generalized lymphadenopathy and localized lymphadenopathy. The pathogenesis of lymphadenopathy is characterized by the inflammation of lymph nodes. This process is primarily due to an elevated rate of trafficking of lymphocytes into the node from the blood, exceeding the rate of outflow from the node. Lymph nodes may also be enlarged secondarily as a result of the activation and proliferation of antigen-specific T and B cells (clonal expansion). Lymphadenopathy is very common, the estimated incidence of lymphadenopathy among children in the United States ranges from 35%- 45%. Patients of all age groups may develop lymphadenopathy. Lymphadenopathy is more commonly observed among children. Common complications of lymphadenopathy, may include: abscess formation, superior vena cava syndrome, and intestinal obstruction. Diagnostic criteria for malignant lymphadenopathy, may include: node > 2 cm, node that is draining, hard, or fixed to underlying tissue, atypical location (e.g. supraclavicular node), associated risk factors (e.g. HIV or TB), fever and/or weight loss, and splenomegaly. On the other hand, diagnostic criteria for benign lymphadenopathy, may include: node < 1 cm, node that is mobile, soft-or tender, and is not fixed to underlying tissue, typical location (e.g. supraclavicular node), no associated risk factors, and palpable and painful enlargement. Laboratory findings consistent with the diagnosis of lymphadenopathy may include elevated lactate dehydrogenase (LDH), mild neutropenia, and leukocytosis. There is no treatment for lymphadenopathy; the mainstay of therapy is treating the underlying condition.
Pathophysiology
Lymph nodes are part of the immune system. As such, they are most readily palpable when fighting infections. Infections can either originate from the organs that they drain or primarily within the lymph node itself, referred to as lymphadenitis.*The pathogenesis of lymphadenopathy is characterized by the inflammation of lymph nodes. This process is primarily due to an elevated rate of trafficking of lymphocytes into the node from the blood, exceeding the rate of outflow from the node.[1]
- The inmune response between the antigen and lymphocyte that leads to cellular proliferation and enlargement of the lymph nodes.
- Lymph nodes may also be enlarged secondarily as a result of the activation and proliferation of antigen-specific T and B cells (clonal expansion).
- On gross pathology, characteristic findings of lymphadenopathy, include:
- Enlarged lymph node
- Soft greasy yellow areas within capsule
- On microscopic histopathological analysis, characteristic findings of lymphadenopathy will depend on the aetiology.
- Common findings, include:[1][2]
Non-specific reactive follicular hyperplasia (NSRFH)
- Large spaced cortical follicles
- Tingible body macrophages, normal dark/light GC pattern
Lymph node metastasis
- Foreign cell population (usually in subcapsular sinuses)
- +/-nuclear atypia
- +/-malignant architecture
Toxoplasmosis
- Large follicles
- Epithelioid cells perifollicular & intrafollicular
- Reactive GCs
- Monocytoid cell clusters
Cat-scratch disease
- PMNs in necrotic area
- "Stellate" (or serpentine) shaped micro-abscesses
- Presence of granulomas
Dermatopathic lymphadenopathy
- Melanin-laden histiocytes
- Histiocytosis
Systemic lupus erythematosus lymphadenopathy
- Blue hematoxylin bodies
- Necrosis
- No PMNs
Epidemiology and Demographics
The estimated incidence of lymphadenopathy in children in the United States ranges from 35%- 45%. It is more common in the pediatric population. Race and gender have no predilection in lymphadenopathy incidence.
Diagnosis
Other Imaging Findings
Positron emission tomography (PET) is used to evaluate clinically diagnosed lymphadenopathy.
Treatment
Surgery
Surgical care involves open biopsy or aspiration of the lymph node and its removal.
Primary Prevention
Good general health and hygiene are helpful in the prevention of any infection.
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Xyz from Other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications, and Prognosis
Diagnosis
Diagnostic Criteria
Malignant Lymphadenopathy
- Node > 2 cm
- Node that is draining, hard, or fixed to underlying tissue
- Atypical location (e.g. supraclavicular node)
- Risk factors (e.g. HIV or TB)
- Fever and/or weight loss
- Splenomegaly
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
X-ray
Echocardiography and Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Interventions
Surgery
Primary Prevention
Secondary Prevention
References
- ↑ 1.0 1.1 Mohseni S, Shojaiefard A, Khorgami Z, Alinejad S, Ghorbani A, Ghafouri A (2014). "Peripheral lymphadenopathy: approach and diagnostic tools". Iran J Med Sci. 39 (2 Suppl): 158–70. PMC 3993046. PMID 24753638.
- ↑ Lymph node enlargment. Wikipedia. https://en.wikipedia.org/wiki/Lymph_node Accessed on May 9, 2016