Atypical adenomatous hyperplasia of the lung
Atypical alveolar hyperplasia of the lung, also atypical adenomatous hyperplasia (abbreviated AAH) and atypical alveolar hyperplasia, is considered the precursor of lung adenocarcinoma. It is typically found beside lung adenocarcinoma in resection specimens.[1]
General
- Generally considered the precursor lesion to adenocarcinoma in situ.[2]
- Typically an incidental finding, i.e. asymptomatic.[3]
Microscopic
Features:[3]
- Enlarged alveolar lining cells with:
- Hobnail morphology - free (luminal) surface area > attached/basal surface area.
- Round or oval nuclei.[1]
- Nuclear hyperchromasia.
- +/-Nuclear enlargement (mild-to-moderate).
- +/-Multinucleation.
- Spaces are typically seen between the cells[1] - important.
- Limited extent:
- <5 mm. †
DDx:
- Adenocarcinoma in situ.
- Lung adenocarcinoma.
Note:
Images
See also
References
- ↑ 1.0 1.1 1.2 Travis, WD.; Brambilla, E.; Noguchi, M.; Nicholson, AG.; Geisinger, KR.; Yatabe, Y.; Beer, DG.; Powell, CA. et al. (Feb 2011). "International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma.". J Thorac Oncol 6 (2): 244-85. doi:10.1097/JTO.0b013e318206a221. PMID 21252716.
- ↑ 2.0 2.1 Sakuma, Y.; Matsukuma, S.; Yoshihara, M.; Nakamura, Y.; Nakayama, H.; Kameda, Y.; Tsuchiya, E.; Miyagi, Y. (Sep 2007). "Epidermal growth factor receptor gene mutations in atypical adenomatous hyperplasias of the lung.". Mod Pathol 20 (9): 967-73. doi:10.1038/modpathol.3800929. PMID 17618248.
- ↑ 3.0 3.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 114. ISBN 978-0781765275.