Lymphadenopathy

Lymphadenopathy, also known as adenopathy, refers to the disease of the lymph nodes where they become abnormal in size or consistency. It is a common and nonspecific clinical sign that can result from various underlying conditions. This essay provides an overview of lymphadenopathy, focusing on its causes, signs, symptoms, diagnosis, and classifications, to aid dentists in understanding this condition in preparation for professional exams.

Signs and Symptoms

Lymphadenopathy can present with a variety of symptoms, including fever, night sweats, sore throat, and runny nose. The nodes may become hard, fixed, and rapidly growing, indicating a potential malignancy such as cancer or lymphoma. Some patients may also experience back pain, constipation, and urinary frequency as associated risk factors.

Causes

Lymphadenopathy can arise from multiple etiologies, including infections, autoimmune diseases, malignancies, histiocytoses, storage diseases, and drug reactions.

Retroperitoneal lymphadenopathies of testicular seminoma embrace the aorta

Infectious causes include bacterial infections such as cat scratch disease, tularaemia, and brucellosis, as well as viral infections like infectious mononucleosis caused by Epstein-Barr virus. Autoimmune diseases like systemic lupus erythematosus and rheumatoid arthritis may also cause generalised lymphadenopathy. Malignancies include both primary (Hodgkin and non-Hodgkin lymphoma) and secondary (metastasis, neuroblastoma, chronic lymphocytic leukaemia) forms.

Other notable causes include bites from venomous snakes and conditions like Kikuchi disease, sarcoidosis, and Kawasaki disease.

Diagnosis

The diagnosis of lymphadenopathy involves several imaging techniques and laboratory evaluations.

Medical ultrasonography of a typical normal lymph node: smooth, gently lobulated oval with a hypoechoic cortex measuring less than 3 mm in thickness with a central echogenic hilum.

Ultrasonography of a suspected malignant lymph node: Absence of the fatty hilum, increased focal cortical thickness greater than 3 cm, Doppler ultrasonography shows hyperaemic blood flow in the hilum and central cortex and/or abnormal (non-hilar cortical) blood flow.

CT scans, MRI scans, and ultrasound are commonly used to assess the morphology and vascular patterns of lymph nodes. Fine-needle aspiration cytology (FNAC) is highly sensitive and specific for evaluating malignant cervical lymphadenopathy. PET-CT scans can help identify occult primary carcinomas and guide treatment decisions.

Classification

Lymphadenopathy can be classified based on size, extent, localisation, and malignancy.

Size

Lymphadenopathy in adults is typically defined by a short axis greater than 10mm, with regional variations. For instance, inguinal lymph nodes may measure up to 20mm, while retropharyngeal nodes should not exceed 8mm.

Extent

Lymphadenopathy can be localised, affecting a specific area, or generalised, involving multiple lymph node regions. Persistent generalised lymphadenopathy (PGL) persists for an extended period without an apparent cause.

Inflammatory localised lymphadenopathy at the right mandibular angle

Localisation

Lymphadenopathy can be further localised to specific regions such as hilar, mediastinal, and bilateral hilar lymphadenopathy. Dermatopathic lymphadenopathy is associated with skin diseases.

Malignancy

Malignant lymphadenopathies mainly refer to lymphomas or lymph node metastasis, and are distinguished from benign types.

Micrograph of dermatopathic lymphadenopathy, a type of lymphadenopathy. H&E stain.

Understanding lymphadenopathy in its various forms is very important for accurate diagnosis and effective management of underlying conditions, whether they are infectious, autoimmune, or malignant in nature.

Self-assessment MCQs (single best answer)

Which of the following is NOT a common symptom associated with lymphadenopathy?

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What is indicated by hard, fixed, and rapidly growing lymph nodes?

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Which imaging technique is highly sensitive and specific for evaluating malignant cervical lymphadenopathy?

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Which of the following diseases is NOT listed as a cause of lymphadenopathy in the essay?

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Generalised lymphadenopathy involving multiple regions without an apparent cause that persists for an extended period is known as:

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Which of the following is a primary malignancy that can cause lymphadenopathy?

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In adults, lymphadenopathy is typically defined by a short axis greater than:

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Which type of lymphadenopathy is associated with skin diseases?

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Which of the following is a typical feature of a normal lymph node on medical ultrasonography?

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Which of the following is NOT a diagnostic tool used in assessing lymphadenopathy?

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