Clinico-etiological Characteristics of Cystic Lung Disease: A Retrospective Study

Introduction: Diffuse cystic lung diseases (CLDs) are a heterogeneous group of uncommon disorders with characteristic imaging appearance. Cystic lung disease is a significant cause of mortality and morbidity with a wide spectrum of radiological presentations and etiological differentials. Though the literature is widely available on radiological approaches to CLD, a knowledge gap exists on the etiological spectrum, especially in the Indian scenario, as it is an orphan group of lung disorders. The interest and experience among pulmonologists regarding CLD are growing with the widespread use of CT scans. Clinical, radiographic, and histological findings are often essential for proper diagnosis, and multidisciplinary approach is required for optimal management of such cases. In our study, through real-world cases, we have highlighted the clinical manifestations and diverse etiological spectrum of CLD. Since these disorders are rare, incurable, and have variable disease progression, the authors have tried to address the holistic approach of this relatively less-understood group of disorders. Aims and objectives: The aim of the study was to identify clinical characteristics and etiological spectrum of patients manifesting with diffuse cystic lung disease radiologically. Materials and methods: In this retrospective analysis, the hospital electronic database was screened with Boolean operations and keywords for cysts OR pneumothorax. Among a total of 4,479 patients admitted to the respiratory ward /ICU during the period of January 2020–September 2022 at a tertiary care center in northern India, 14 patients with radiological diagnosis of CLD matched the relevant search. All relevant data of these patients were retrieved from the records. Results: Our patients presented predominantly with symptoms of cough and breathlessness. About 4 patients had pneumothorax as the first presentation. The mean age of presentation was 42.14 (standard deviation 12.6, age range 16–62 years). About 64% (n = 9/15) patients were females. The various etiologies identified were lymphangioleiomyomatosis (LAM), lymphocytic interstitial pneumonia, Birt–Hogg–Dube syndrome, hypersensitivity pneumonitis, Pneumocystis jirovecii pneumonia, and cystic metastasis, and in one patient, no definite cause was found despite detailed evaluation. Conclusion: Cystic lung disorders are a less commonly diagnosed entity with rare etiologies. In our study, we found a female preponderance and LAM as the commonest CLD. Pneumothorax is a sentinel event and commonly the presenting complaint in CLD. Identification of the etiology can help in institution of definite therapy when available. In view of unpredictable disease progression and outcome, these diseases warrant follow-up and imaging surveillance.