The acinus or primary pulmonary lobule (the basic unit of gas exchange) consists of one terminal bronchiole, two to five generations of respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
Emphysema is classified into three subtypes based on the portion of the acinus that is involved.
Panlobular emphysema, also referred to as panacinar emphysema, affects the acinus of the entire secondary lobule.
Primary bronchiolar disorders are separated from diseases primarily affecting more distal components of the pulmonary acinus and large airway diseases in which prominent secondary bronchiolar changes may be seen.
A spectrum of airborne organic particulate matter, appropriately sized to reach pulmonary acini , produces this disease.
In cases with moderate or advanced changes, marked immunoreactivity was observed in the interlobular area and in the area surrounding both the acini and intralobular ducts.
The mass also contained cystic spaces lined by columnar epithelium, sebaceous glands, cartilage, smooth muscle, and pancreatic acini .
Small residual ducts and islands of intact salivary gland acini predominantly composed of serous-type glandular epithelium were present.
The lesion displayed unremarkable pancreatic lobules with acini , ducts, and islets of Langerhans cells.
The airway wall is composed of many interrelated structural components such as epithelium, connective tissue, vessels, muscle, and mucus-secreting gland acini .