Mediastinal lymphadenopathy: a practical approach

ABSTRACT

Introduction: Mediastinal lymphadenopathy is secondary to various benign and malignant etiologies. There is a variation in the underlying cause in different demographic settings. The initial clue to the presence of enlarged mediastinal lymph nodes is through thoracic imaging modalities. Malignancy (Lung cancer, lymphoma, and extrathoracic cancer) and granulomatous conditions (sarcoidosis and tuberculosis) are the most common causes. For a confident diagnosis, the clinician must choose from several available options and integrate the clinical, radiological, and pathology findings. An accurate diagnosis is necessary for optimal management.

Areas covered: We performed a search of the PUBMED database to identify relevant articles on the causes, imaging modalities, and interventional modalities to diagnose these conditions. We discuss a practical approach toward the evaluation of a patient with mediastinal lymphadenopathy.

Expert opinion: Mediastinal lymphadenopathy is a commonly encountered clinical problem. Treating physicians need to be aware of the clinico-radiological manifestations of the common diagnostic entities. Selecting an appropriate tissue diagnosis modality is crucial, with an intent to use the least invasive technique with good diagnostic yield. Endosonographic modalities (EBUS-TBNA, EUS-FNA, and EUS-B-FNA) have emerged as the cornerstone to most patients’ diagnosis. An accurate diagnosis translates into favorable treatment outcomes.

KEYWORDS:

• Mediastinum
• lymph node
• sarcoidosis
• lung cancer
• tuberculosis
• endobronchial ultrasound

Article highlights

• Mediastinal lymphadenopathy is a common clinical problem with varied underlying etiologies.

• Malignancy (Lung cancer) and granulomatous causes (Sarcoidosis and Tuberculosis) are the most typical causes.

• Radiological investigations can suggest the presence of enlarged mediastinal lymph nodes. Very often, the diagnosis is incidental.

• The diagnostic investigations available for tissue sampling can broadly be grouped into minimally invasive and invasive techniques.

• Minimally invasive endosonography techniques such as EBUS-TBNA, EUS-FNA, and EUS-B-FNA are safe. These modalities are the preferred first-line investigations in most patients.

• Integration of clinical, radiological, and pathology investigations allows a confident diagnosis in a majority.

• The minimally invasive techniques have mainly replaced invasive procedures like mediastinoscopy, which were traditionally considered the gold standard for diagnosis.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.