Management of Mediastinal Lymphadenopathy

Initial Assessment and Risk Stratification

The American College of Radiology recommends that nodes <15mm in asymptomatic patients require no further workup, while nodes 15-25mm need clinical correlation with consideration of follow-up imaging, and nodes >25mm require tissue diagnosis via minimally invasive techniques as first-line approach, with a high level of evidence 1, 2
For nodes 15-25mm, evaluation for associated pulmonary findings, such as pneumonia or interstitial lung disease, is necessary, and if explainable by benign conditions, a 3-month follow-up CT may be considered instead of immediate biopsy, with a moderate level of evidence 1
Nodes >25mm are always considered pathologic and require tissue diagnosis, with a high level of evidence 1, 2

The American Thoracic Society recommends using minimally invasive sampling techniques, such as EBUS-NA or EUS-NA, as the first-line approach for discrete enlarged nodes or PET-avid nodes, with a high level of evidence 4, 6
EBUS-NA has a sensitivity of 93% and specificity of 100%, while EUS-NA has a sensitivity of 92-97% and specificity of 100%, with a high level of evidence 8

Young males with mediastinal lymphadenopathy should be considered for lymphoma, seminoma, or nonseminomatous germ cell tumors, and an FDG PET/CT should be obtained, with a moderate level of evidence 1, 2
Patients with B symptoms, such as fever, night sweats, or weight loss, should undergo FDG PET/CT regardless of node size, with a moderate level of evidence 2, 3

Congestive heart failure can cause nodes >2cm, and a trial of diuretic therapy with follow-up CT in 3 months may be considered, with a low level of evidence 1, 2
Interstitial lung diseases can cause lymphadenopathy, and the prevalence and extent of lymphadenopathy correlate with disease severity, with a moderate level of evidence 1, 2

Relying on size alone to determine the need for tissue diagnosis is not recommended, as normal-sized nodes can harbor microscopic metastases in 20-25% of patients with central tumors, with a high level of evidence 4, 5, 2
Assuming malignancy in patients with a cancer history is not recommended, as benign causes, such as inflammation or sarcoidosis, can occur in 40% of patients with prior extrathoracic malignancy, with a low level of evidence
Accepting a negative needle biopsy as definitive when clinical suspicion is high is not recommended, and surgical staging should be considered, with a high level of evidence 4, 6