Thoracic Fluid Collection



Thoracic Fluid Collection


Paula J. Woodward, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Bilateral Pleural Effusion



    • Hydrothorax


  • Unilateral Pleural Effusion



    • Chylothorax


  • Pericardial Effusion


Less Common



  • Effusions Associated with Lung Masses



    • Bronchopulmonary Sequestration


    • Congential Cystic Adenomatoid Malformation (CCAM)


  • Masses That Can Mimic Simple Fluid Collection



    • Unilocular CCAM


    • Congenital Diaphragmatic Hernia


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • First determine where the fluid is located



    • Pleural space, pericardial space or within a mass


  • Pleural effusion



    • Routine four chamber heart view



      • Curvilinear, anechoic fluid


      • Echogenic lung displaced medially


    • Coronal chest view



      • Lung displaced superiorly and medially


      • “Wing-like” lungs float in fluid


  • Pericardial effusion



    • Fluid collection surrounds fetal heart


    • If large, heart is seen beating in a “bag of water”


    • Lungs will be compressed posteriorly, not free floating


  • Large, unilocular cystic masses may simulate pleural effusion



    • Masses are rounded or ovoid


    • Have mass effect on lungs and mediastinal structures



      • Lung shifted away from fluid, not surrounded by fluid as in a pleural effusion


Helpful Clues for Common Diagnoses



  • Hydrothorax



    • Serous fluid collection


    • Effusions are bilateral and symmetric


    • Hallmark finding in hydrops fetalis (both immune and nonimmune)


    • Hydrops defined as fluid accumulation in 2 or more body cavities



      • Pleural effusion


      • Ascites


      • Skin edema


      • Pericardial fluid


    • Polyhydramnios and placentomegaly also often present if there is hydrops


    • Anomalies commonly associated with effusions/hydrops



      • Cystic hygroma (Turner syndrome) most common


      • Trisomy 21 (other markers usually seen); trisomy 18, 13 less likely


      • Cardiac defects


      • Cardiac arrhythmia


      • Infection


      • Cystic adenomatoid malformation (< 10% have hydrops)


    • Fetal masses causing high output failure (and possible hydrops)



      • Sacrococcygeal teratoma


      • Goiter


      • Vascular shunting: Vein of Galen malformation, arteriovenous fistulas, hepatic hemangioendothelioma, placental chorioangioma


    • First trimester pleural effusion



      • Can be seen as early as 7 weeks


      • Associated with increased nuchal translucency


      • Poor prognosis when present before 15 wks


      • Aneuploidy common: Turner syndrome most likely


  • Chylothorax



    • Chylous fluid collection


    • Effusion is unilateral


    • Primary congenital lymphatic defect



      • Atresia, fistula, or absence of thoracic duct


    • Thoracic duct crosses from right to left at 5th thoracic level



      • Level of obstruction determines right versus left-sided effusion


      • Equal incidence of right and left-sided effusions


    • Fluid is anechoic



      • Only after neonatal feeding will chylous fluid appear “milky”


    • Mass effect common




      • Mediastinal shift


      • Flattened diaphragm


    • May lead to hydrops when large



      • Consider performing fetal thoracentesis if evidence of fetal compromise


    • 5% associated with aneuploidy



      • Turner syndrome


      • Trisomy 21


      • Noonan syndrome


    • Amniocentesis warranted


    • 15% resolve in fetal life


    • Near 100% survival without hydrops and normal chromosomes


  • Pericardial Effusion



    • Seen best on standard four chamber view


    • Lenticular or oval collection of fluid adjacent to, or surrounding heart


    • Trace of fluid along one ventricular wall is normal



      • Can be up to 2 mm


      • Majority of fetuses (50-80%) have trace fluid if careful search done


      • Generally transient


      • If fetus not at increased risk, follow-up not necessary


    • Significant effusion if fluid surrounds atria as well as ventricles


    • Pericardial effusion seen in many conditions



      • Evaluate heart for structural abnormality, arrhythmia or mass


      • Look for other signs of hydrops


      • Look for signs of congenital infection


      • Look for anemia


Helpful Clues for Less Common Diagnoses

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Aug 10, 2016 | Posted by in OBSTETRICS | Comments Off on Thoracic Fluid Collection

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