The role of computed tomography in a diagnostic approach to cystic lung diseases and their differential diagnosis

Abstract

In everyday routine, lung cysts are commonly seen in Computed Tomography, as far as manydifferentconditionsanddiseasesareassociatedwithaircysts.Thus,correctdiag-many different conditions and diseases are associated with air cysts. Thus, correct diag-nosisofcysticlungdiseases,whichshowawidespectrum,isachallengeforradiologists.nosis of cystic lung diseases, which show a wide spectrum, is a challenge for radiologists. Fordiagnosisanddifferentialdiagnosis,firstofall,cystsshouldbedistinguishedfromFor diagnosis and differential diagnosis, fi rst of all, cysts should be distinguished from suchotherairfilledlesions,likecavities,bullae,pneumatocele,emphysema,honeycomb-such other air fi lled lesions, like cavities, bullae, pneumatocele, emphysema, honeycomb-ingandcysticbronchiectasis.Second,cystscanbecategorizedassingle/localizedversusing and cystic bronchiectasis. Second, cysts can be categorized as single/localized versus multiple/diffuse.Solitary/localizedcystsincludeincidentalcysts,congenitalcysticdis-multiple/diffuse. Solitary/localized cysts include incidental cysts, congenital cystic dis-easesandcysticcancers.Multiple/diffusecystscanbefurthercategorizedaccordingtoeases and cystic cancers. Multiple/diffuse cysts can be further categorized according to thepresenceorabsenceofassociatedradiologicfindings.Multiple/diffusecystswithoutthe presence or absence of associated radiologic fi ndings. Multiple/diffuse cysts without associatedfindingsincludelymphangioleiomyomatosisandBirt-Hogg-Dubésyndrome.associated fi ndings include lymphangioleiomyomatosis and Birt-Hogg-Dubé syndrome. Multiple/diffusecystsmaybeassociatedwithground-glassopacityorsmallnodules.Multiple/diffuse cysts may be associated with ground-glass opacity or small nodules. Multiple/diffusecystswithnodulesincludeLangerhanscellhistiocytosis,cysticmetas-Multiple/diffuse cysts with nodules include Langerhans cell histiocytosis, cystic metas-tasisandamyloidosis.Multiple/diffusecystswithground-glassopacityincludepneumo-tasis and amyloidosis. Multiple/diffuse cysts with ground-glass opacity include pneumo-cystispneumonia,desquamativeinterstitialpneumoniaandlymphocyticinterstitialpneu-cystis pneumonia, desquamative interstitial pneumonia and lymphocytic interstitial pneu-monia.Thestepwiseradiologicdiagnosticapproachcanbehelpfulinreachingacorrectmonia. The stepwise radiologic diagnostic approach can be helpful in reaching a correct diagnosisforvariouscysticlungdiseases.diagnosis for various cystic lung diseases.