Lucent Lung Mass



Lucent Lung Mass


Daniel J. Podberesky, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Cystic Adenomatoid Malformation


  • Congenital Lobar Emphysema


  • Congenital Diaphragmatic Hernia


  • Pneumatocele


  • Pulmonary Abscess


Less Common



  • Lung Contusion and Laceration


  • Loculated Pneumothorax


  • Bulla


  • Bronchial Atresia


Rare but Important



  • Traumatic Diaphragmatic Hernia


  • Pleuropulmonary Blastoma


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Lucent lung masses in children most frequently either congenital or infectious in nature


  • History very helpful


  • CT frequently necessary to narrow differential


Helpful Clues for Common Diagnoses



  • Cystic Adenomatoid Malformation



    • a.k.a. congenital pulmonary airway malformation (CPAM)


    • Diagnosis can be made prenatally with ultrasound and fetal MR


    • Type 1



      • Single or multiple 2-10 cm cysts


      • May contain air-fluid levels


      • Good prognosis


    • Type 2



      • Multiple small cysts (0.5-2 cm)


      • Variable prognosis


    • Type 3



      • Innumerable microscopic cysts


      • Appears solid


      • Poorer prognosis


    • Evidence of associated mass effect



      • Mediastinal shift


      • Compression of adjacent normal lung


    • Can coexist with other pulmonary malformations, such as sequestration


    • Infection risk


    • Small malignancy risk



      • Bronchioalveolar carcinoma


      • Pleuropulmonary blastoma


      • Rhabdomyosarcoma


  • Congenital Lobar Emphysema



    • Overdistension of lobe of lung



      • Left upper > right middle > right upper lobe


    • Multifocal in only ˜ 5%


    • During 1st few days of life, affected lobe may be opacified by lung fluid


    • Hyperlucent, hyperexpanded lobe thereafter



      • Evidence of associated mass effect


    • ˜ 15% have associated congenital heart disease


  • Congenital Diaphragmatic Hernia



    • Bochdalek (90%)



      • Posterior


    • Morgagni (10%)



      • Anterior


    • Left (75%), right (25%)


    • Multicystic mass in chest when stomach/bowel involved


    • Associated mass effect


    • Associated pulmonary hypoplasia


    • Enteric tube may enter mass


    • Diagnosis can be made prenatally with ultrasound and fetal MR


  • Pneumatocele



    • Thin-walled cyst


    • Can be secondary to infection or trauma


    • Frequently resolves spontaneously


  • Pulmonary Abscess



    • Frequently anaerobic infection from aspirated oral contents


    • Can also be seen with Staph, Strep, fungi, mycobacteria, and parasites


    • Irregularly shaped lucent mass with internal air-fluid level



      • Size of air-fluid level similar on frontal and lateral projections


    • Thick, shaggy rind


    • Look for other signs of infection



      • Pleural effusion/empyema


      • Lung consolidation


    • Typically resolve with IV antibiotics and do not require drainage


Helpful Clues for Less Common Diagnoses



  • Lung Contusion and Laceration



    • Penetrating or blunt trauma with large shearing forces can result in laceration



    • Commonly associated with pneumothorax


    • Lucent lung cavity filled with air &/or fluid


    • Complications



      • Bronchopleural fistula


      • Pulmonary abscess


      • Pneumatocele


      • Air embolism


  • Loculated Pneumothorax



    • May mimic lucent lung mass


    • Typically found within fissure or in subpulmonic location


    • CT will confirm pleural rather than parenchymal source


  • Bulla



    • Thin-walled pulmonary parenchymal air-filled space


    • Commonly seen with emphysema



      • α-1-antitrypsin in children/adolescents


      • Idiopathic


    • Can be seen with connective tissue disorders such as Marfan syndrome


    • Superinfection



      • Look for air-fluid level


    • Can rupture and cause pneumothorax


  • Bronchial Atresia



    • Noncommunication of segmental bronchus with central airway


    • Likely a result of in utero vascular insult


    • Can coexist with other pulmonary malformations, such as sequestration


    • Left upper > left lower > right middle lobe


    • Hyperlucent and hyperexpanded lobe


    • Central tubular/branching density representing mucoid plugged bronchus



      • “Finger in glove” appearance


Helpful Clues for Rare Diagnoses

Tags:
Aug 10, 2016 | Posted by in PEDIATRICS | Comments Off on Lucent Lung Mass

Full access? Get Clinical Tree
Get Clinical Tree app for offline access