Unilateral Hilar Mass



Unilateral Hilar Mass


Christopher M. Walker, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Bronchogenic Carcinoma


  • Lymphadenopathy Associated with Infections


Less Common



  • Lymphadenopathy Secondary to Metastatic Disease


  • Lymphoma


Rare but Important



  • Sarcoidosis


  • Pulmonary Artery Enlargement


  • Bronchogenic Cyst


  • Carcinoid


  • Castleman Disease


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Infection and malignancy dominate differentials in category


  • Key features of clinical history help determine diagnosis



    • Signs and symptoms of infection


    • Presence of known malignancy


  • Clues to distinguish hilar mass from lymphadenopathy



    • Nodes are well defined and smooth and occur in nodal stations


    • Masses may have infiltrating edges


Helpful Clues for Common Diagnoses



  • Bronchogenic Carcinoma



    • Small cell lung carcinoma



      • Mediastinal mass involving 1 hilum


      • Typically large at diagnosis


      • May cause lobar or complete lung collapse


      • Ill-defined borders on CT and radiographs


      • Frequently metastatic at presentation


    • Squamous cell carcinoma



      • Most common tumor to cavitate


      • Often central in location


    • Adenocarcinoma



      • Spiculated lung nodule or mass


      • Ipsilateral hilar lymphadenopathy


    • Important to note contralateral mediastinal/hilar or supraclavicular lymphadenopathy



      • Could indicate N3 disease, which is unresectable


    • Abnormal lymph nodes



      • ≥ 1.2 cm short axis diameter for subcarinal lymph nodes


      • ≥ 1 cm short axis diameter for all other nodal groups


  • Lymphadenopathy Associated with Infections



    • Signs/symptoms of infection


    • Seen with



      • Primary tuberculosis, endemic fungi, mononucleosis, severe bacterial pneumonia


    • TB: Nodes show central necrosis


    • Ipsilateral lung consolidation


    • Travel history important for endemic fungi


Helpful Clues for Less Common Diagnoses



  • Lymphadenopathy Secondary to Metastatic Disease



    • History of extrathoracic malignancy


    • Common primary tumors



      • Head and neck malignancies, breast carcinoma, melanoma, and genitourinary malignancies


    • Lymph nodes are typically sharply marginated and round


    • Enhancing lymph nodes



      • Renal cell carcinoma, thyroid carcinoma, or melanoma


    • Necrotic lymph nodes



      • Breast carcinoma, testicular carcinoma, or renal cell carcinoma


    • Calcified lymph nodes



      • Treated metastases, thyroid carcinoma, mucinous adenocarcinoma


  • Lymphoma



    • Bulky asymmetric mediastinal/hilar lymphadenopathy


    • Displaces but rarely constricts mediastinal structures


    • B symptoms



      • Night sweats, fever, and weight loss


    • Hodgkin lymphoma



      • Prevascular, paratracheal, and aorticopulmonary nodal involvement in nearly all cases


      • 25-35% have concomitant hilar nodal disease


      • Nodes may calcify after radiotherapy



      • Spreads via contiguous lymph node groups


      • Lung disease in 10% of patients


      • Peak incidence in 3rd and 8th decades of life


      • Ann Arbor system stages disease


    • Non-Hodgkin lymphoma (NHL)



      • Thoracic involvement in 50% of cases


      • Most patients with thoracic disease have anterior mediastinal disease


      • Hilar adenopathy in 10-20% of patients with thoracic involvement


      • Binodal peak incidence in 5th-8th decades of life


      • Spreads via noncontiguous lymph node groups


      • Multifocal disease at presentation is observed frequently


    • Extrathoracic lymphadenopathy seen more commonly with NHL


Helpful Clues for Rare Diagnoses



  • Sarcoidosis



    • Unilateral hilar enlargement seen in minority of cases


    • Perilymphatic distribution of lung nodules



      • Nodules along fissures, pleural surfaces, and bronchovascular bundles


      • Predilection for upper lungs


    • Child-bearing females


  • Pulmonary Artery Enlargement



    • CECT diagnostic


    • Causes include



      • Pulmonary valve stenosis


      • Pulmonary artery aneurysm


      • Intravascular tumor


      • Proximal interruption of pulmonary artery


    • Pulmonary artery aneurysm secondary to



      • Trauma from pulmonary arterial catheter


      • Mycotic aneurysm


      • Collagen vascular diseases


    • Main and left pulmonary artery enlargement



      • Pulmonic valve stenosis


      • Absent pulmonary valve


  • Bronchogenic Cyst



    • Well-defined spherical mass


    • Highly variable internal HU secondary to varying protein content


    • Presence of air usually indicates infection


    • May displace or compress mediastinal structures


    • Wall is thin or not seen


    • No internal contrast enhancement


    • Abrupt increase in size secondary to hemorrhage or infection


  • Carcinoid

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Aug 8, 2016 | Posted by in CARDIOLOGY | Comments Off on Unilateral Hilar Mass

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