Cystic Lung Diseases Causing Spontaneous Pneumothorax

Abstract

Surgical specimens resulting from a spontaneous pneumo- thorax (SP) are commonly encountered in the general surgical pathology practice. Many of the SP cases are primary pneumothorax with no underlying lung diseases. Specimens with primary pneumothorax show nonspecific pneumotho- rax-related changes, which are important to recognize to exclude the true underlying lung diseases. A variety of dis- ease entities may lead to diffuse cystic changes in the lungs, causing secondary pneumothorax. Some of the diseases are progressive and can cause irreversible damage to the lungs if not treated timely. Diagnosis of cystic lung diseases caus- ing secondary pneumothorax is important for the treatment of the diseases and the prevention of future episodes of pneumothorax. Lymphangioleiomyomatosis and Langerhans cell histiocytosis are two common conditions causing diffuse cystic changes in the lungs. They are discussed in greater de-tail in this review, given their overlapping features in patient characteristics, radiological findings, and pathologic findings. a diagnosis of exclusion. Specimens from these patients will show a spectrum of pneumothorax-related changes, which are important to recognize to exclude the true underlying lung diseases. The pneumothorax-related changes include pleural fibrosis with or without blebs, thick-walled blood vessels, and eosinophilic-rich chronic inflammation. 6–8 The underlying lung parenchyma may show distal acinar em-physema and reactive pneumocyte hyperplasia.