**4.2.3 Paraseptal (distal acinar) emphysema**

It usually involves the distal airway structures, alveolar ducts, and alveolar sacs around the septae of the lungs or pleura(Hogg & Timens,2009;Kim et al.,1991 as cited in Shapiro SD,2010). Apical and giant bullae described in this subtype may lead to spontaneous pneumothorax or compression of adjacent lung tissue.

#### **4.3 Other pathologic variants mimicking emphysema**
