Commonest type of emphysema is ?
Ans. is 'c' i.e., Irregular Types of Emphysema o Emphysema is classified according to its anatomic distribution within the lobule. o There are four major types of emphysema ? Centriacinar (centrilobular) emphysema o Centriacinar emphysema is the most common type of emphysema seen clinically. o It is chracterized by involvement of respiratory bronchioles, i.e. central (proximal) pa of the acinus. o So, both emphysematous and normal airspaces exist within the same acinus and lobule. o The lesions are more common and more severe in the upper lobe, paicularly in the apical segments. o This is the type of emphysema that occurs predominantly in heavy smokers and usually coexists with chronic bronchitis. Panacinar (Panlobular) emphysema o The acini are uniformly enlarged from the level of the respiratory bronchiole to the terminal blind alveoli. o This type of emphysema tends to occur more commonly in the lower zones and in the anterior margins of the lung, and it is usually most severe at the base. o This type of emphysema is associated with al -antittypsin deficiency. Distal acinar (Paraseptal) emphysema o This type of emphysema involves distal pa of the acinus, while proximal pa is normal. o It is localized adjacent to the pleura, along perilobular septa. o The involvement is seen adjacent to areas of fibrosis, scarring, or atelectasis and is usually more severe in the upper half of lungs. o This type of emphysema is a common cause of spontaneous pneumothorax in young adults. 4.Irregular emphysema (Para-cicatricial emphysema) 3 The acinus is involved irregularly and is almost invariably associated with scarring. o It is the most common type of emphysema histologically. Note :? o There should be no confusion about the most common type of emphysema :? "Irregular emphysema may be the most common form of emphysema". Robbin's 8thie 684 "Irregular emphysema may be the most common form of emphysema". ________ Pathological basis of disease "Irregular emphysema may be most common type of emphysema".____ Thurlbeck's chronic airflow obstruction "Irregular emphysema is always associated with scarring and is the most common form of emphysema".Pathology of lung o However, this type of emphysema is not clinically significant as most patients remain asymptomatic and this type of emphysema is most frequent emphysema at autopsy. "Irregular emphysema is at once the most common and least significant form of emphysema". -- Pathology basic and systemic o On the other hand, centriacinar emphysema is the most common form of emphysema which is clinically significant, i.e. producing COPD. "Centriacinar emphysema is the most common form of emphysema producing obstructive respiratory disease".................................Pathology basic and systemic So, o Most common form of emphysema --> Irregular o Most common histological form of emphysema --> Irregular o Most common form of emphysema seen clinically --> Centriacinar
Centriacinar
Obstructed
Irregular
Panacinar