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Bilateral hilar lymphadenopathy
ChestCT / Radiograph
Symmetric enlargement of both hila. Symmetry, associated parenchymal pattern and clinical context distinguish sarcoidosis from infective and malignant causes.
Differential
Sarcoidosis
common- •Symmetric hilar + right paratracheal nodes (1-2-3 / Garland triad)
- •Perilymphatic upper-zone nodules; may calcify (eggshell)
- •Young adult, often asymptomatic
Reactive (infection: TB, viral, mycoplasma)
common- •TB tends to be asymmetric with necrotic (low-density) nodes
- •Consolidation/tree-in-bud; acute illness
Lymphoma
less-common- •Bulky, often asymmetric nodes including anterior mediastinum
- •B symptoms; may become symmetric
Metastatic disease
less-common- •Known primary (lung, breast, RCC, testicular, head & neck)
- •Associated pulmonary nodules/lymphangitis
Silicosis / coal worker’s pneumoconiosis
rare- •Occupational exposure; upper-zone nodules
- •Eggshell nodal calcification
Berylliosis
rare- •Occupational beryllium exposure; sarcoid-like adenopathy
- •Positive lymphocyte proliferation test
Key discriminators
- •Symmetry (symmetric favours sarcoid; asymmetric favours malignancy/TB)
- •Nodal density (necrotic in TB; eggshell in sarcoid/silicosis)
- •Associated parenchymal pattern and distribution
- •Clinical context and occupational/exposure history
- •Presence of a known primary malignancy
Work-up / next steps
- 1.Contrast CT to assess symmetry, nodal density and parenchyma
- 2.Serum ACE/calcium and occupational history
- 3.Tuberculin/IGRA testing where TB is plausible
- 4.Endobronchial ultrasound-guided nodal biopsy for confirmation
References
- Radiopaedia: Bilateral hilar lymphadenopathy.
- Sharma A et al. Bilateral hilar lymphadenopathy. Clin Radiol.
Educational clinical decision support only. This differential does not make a diagnosis, is not a medical device, and must never substitute for interpretation by a qualified radiologist correlated with the full clinical picture and prior imaging.