Atypical adenomatous hyperplasia (AAH) is a
hyperplastic
Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferatio ...
lesion of the epithelial lining of
pulmonary alveoli.
Tumorigenesis
A multi-step carcinogenesis hypothesis suggests a progression from
atypical adenomatous hyperplasia (AAH) through
bronchioalveolar carcinoma (BAC) to
invasive adenocarcinoma
Invasive may refer to:
* Invasive (medical) procedure
* Invasive species
* Invasive observation, especially in reference to surveillance
*Invasively progressive spread of disease from one organ in the body to another, especially in reference to ca ...
(AC), but to date this has not been formally demonstrated.
References
Pulmonary lesion
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