Citation, DOI & article data
Pulmonary cysts are round, thin-walled, low attenuation spaces/lucencies in the lung. Lung cysts usually contain air but occasionally also contain fluid or solid material 5.
They are generally seen in patients <40 years of age and are associated with a low BMI 9.
In contradistinction to all other organs, the term cyst as used in the lung is a misnomer, as it usually refers to a contained focus of gas, not fluid.
Pulmonary cysts can be congenital or acquired. Multiple lung cysts in a child may be associated with an underlying process although this is rare, e.g. pleuropulmonary blastomas 1.
There are several specific types of thin-walled cystic spaces in the lungs 6,7:
- bleb: pleural/subpleural, ≤1-2 cm diameter
- bulla: pleural/subpleural, ≥1-2 cm diameter
- honeycombing: subpleural stacks of cysts, typically 3-10 mm diameter with walls 1-3 mm in thickness
- pneumatocele: usually transient cystic airspace within the lung, usually due to pneumonia or trauma
There are several mimics of pulmonary cysts:
- pulmonary cavity: surrounded by mass, nodule, or consolidation, creating wall thickness >2-4 mm 4-6
- emphysema: lucencies without wall and with central vessel
- cystic bronchiectasis: contiguous with other airways
- occasionally lung cancer may appear as thin walled cystic lung cancer
- 1. Priest JR, Williams GM, Hill DA et-al. Pulmonary cysts in early childhood and the risk of malignancy. Pediatr. Pulmonol. 2009;44 (1): 14-30. doi:10.1002/ppul.20917 - Pubmed citation
- 2. Dähnert W. Radiology Review Manual. Lippincott Williams & Wilkins. (2011) ISBN:1609139437. Read it at Google Books - Find it at Amazon
- 3. Webb WR, Higgins CB. Thoracic Imaging, Pulmonary and Cardiovascular Radiology. Lippincott Williams & Wilkins. (2010) ISBN:1605479764. Read it at Google Books - Find it at Amazon
- 4. Gadkowski LB, Stout JE. Cavitary pulmonary disease. Clin. Microbiol. Rev. 2008;21 (2): 305-33, table of contents. doi:10.1128/CMR.00060-07 - Free text at pubmed - Pubmed citation
- 5. Cantin L, Bankier AA, Eisenberg RL. Multiple cystlike lung lesions in the adult. AJR Am J Roentgenol. 2010;194 (1): W1-W11. doi:10.2214/AJR.09.3540 - Pubmed citation
- 6. Hansell DM, Bankier AA, MacMahon H, McLoud TC, Müller NL, Remy J. Fleischner Society: glossary of terms for thoracic imaging. (2008) Radiology. 246 (3): 697-722. doi:10.1148/radiol.2462070712 - Pubmed
- 7. Ryu JH, Swensen SJ. Cystic and cavitary lung diseases: focal and diffuse. (2003) Mayo Clinic proceedings. 78 (6): 744-52. doi:10.4065/78.6.744 - Pubmed
- 8. Deng H, Zhang J, Zhao S, Zhang J, Jiang H, Chen X, Wang D, Gao J, Wu C, Pan L, Wang Y, Xue X. Thin-wall cystic lung cancer: A study of 45 cases. (2018) Oncology letters. 16 (1): 755-760. doi:10.3892/ol.2018.8707 - Pubmed
- 9. Araki T, Nishino M, Gao W, Dupuis J, Putman RK, Washko GR, Hunninghake GM, T O'Connor G, Hatabu H. Pulmonary cysts identified on chest CT: are they part of aging change or of clinical significance?. Thorax. 2015 Dec 1;70(12):1156-62. Pubmed