Cystic Lung Disease 101

This past week at Morning Report we discussed about cystic lung disease. Below is pertinent information regarding lung cysts and what to include in the differential:

  • Lung cyst is defined as a round parenchymal lucency or area of low attenuation with a thin wall
  • Cysts can be found on CT scans (particularly high-res) and requires a work-up as they are never normal
  • Differential for diseases characterized by lung cysts is broad ranging from isolated chest disorders to rare multisystem diseases
  • Characteristic findings on imaging, clinical history, and pathological findings (i.e. biopsy) may help determine the diagnosis
  • Important to distinguish pulmonary cyst from cavity
  • Cysts usually are thin walled, <2-3mm thick) and contain air but occassionally fluid or solid material
  • Cavities are defined as gas-filled spaces that develop in an area of pulmonary consolidation, mass, or nodule
  • Differential to consider in patient who presents with cysts:
    • Centrilobular emphysema
    • Lymphangioleiomyomatosis (LAM)
    • Langerhans cell histiocytosis
    • Lymphocytic interstitial pneumonia (LIP)
    • Pulmonary metastasis
    • Barotrauma/ARDS
    • Birt Hogg Dube syndrome
    • Desquamative interstitial pneumonia (DIP)
    • End stage IPF with honeycombing
    • Sarcoidosis