Abstract
Diffuse cystic lung diseases (DCLDs) are a group of heterogeneous lung diseases that are characterized by inflated spaces or cysts within the lung parenchyma. They also exhibit similar imaging characteristics and clinical manifestations compared with those of cystic lesions, such as pulmonary cavities, emphysema, bronchiectasis and honeycomb lung. The most common DCLDs encountered in the clinic include lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome, Langerhans cell histiocytosis and lymphocytic interstitial pneumonia. In particular, accurate diagnosis of DCLDs in terms of the different lesions found is important, because their clinical courses, prognoses and treatment strategies vary widely. However, because DCLDs usually have overlapping clinical presentations, diagnosis typically requires a combination of clinical considerations that take into account characteristics of the cyst, its distribution, organ of origin and background parenchymal findings. The present report documents the case of a 73-year-old man diagnosed with desquamative interstitial pneumonia (DIP). The patient was admitted to the hospital due to chest tightness, shortness of breath and intermittent fever. The patient had been a smoker for >60 years and had stopped smoking for 6 months before being admitted. A transbronchial lung biopsy, bronchoscopy and alveolar lavage cytopathogen culture were performed to confirm the diagnosis of desquamative interstitial pneumonia (DIP). The patient was treated with hormonal therapy and advised to abstain from smoking. The diagnosis of DIP in comparison with other DCLDs was summarized for the purpose of providing a clinical basis for the accurate clinical diagnosis of DIP and the development of evidence-based practice guidelines.