Lung
Other nonneoplastic disease
Atelectasis
Author: Elliot Weisenberg, M.D.
Last author update: 1 December 2011
Last staff update: 9 August 2020
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed search: round atelectasis [title] OR rounded atelectasis [title]
Cite this page: Weisenberg E. Atelectasis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungnontumorroundedat.html. Accessed April 25th, 2024.
Definition / general
- Incomplete expansion of lung or collapse of previously inflated lung, due to obstruction / resorption, compression or contraction
- Obstruction: resorption of oxygen causes collapse and mediastinal shifts towards affected lung; due to mucus plugs, asthma, chronic bronchitis, bronchiectasis, postoperative changes, foreign bodies, but not usually due to tumors, which cause only subtotal obstruction
- Compression: due to fluid (congestive heart failure), air (pneumothorax), tumor and blood; causes mediastinal shifts away from affected lung
- Contraction: due to fibrosis (restrictive lung disease)
- Patchy: due to loss of surfactant in acute respiratory distress syndrome
- Rounded: Localized area of subpleural lung collapse with associated pleural fibrosis; patients usually asymptomatic with occupational exposure to asbestos; usually posterior portion of a lower lobe
Gross description
- Rounded: lung shows ill defined atelectasis with deeply invaginated pleural folds, which may disappear during grossing
Microscopic (histologic) description
- Rounded: pleural fibrosis and invagination (use elastic stains to highlight) and atelectasis
