Lung carcinoma with diffuse cysts repeatedly misdiagnosed as pulmonary infections and lymphoid interstitial pneumonia: A case report.

INTRODUCTION: Diffuse cystic lung diseases comprise a heterogeneous group of pulmonary disorders, with most cases being benign and malignant instances being rare.

CASE REPORT: We present an unusual case of lung adenocarcinoma characterized by the progressive diffusion of cystic lesions. The patient, initially diagnosed with a pulmonary infection and lymphoid interstitial pneumonia, underwent repeated misdiagnoses. Ultimately, the diagnosis was confirmed using radial endobronchial ultrasound-guided-transbronchial cryobiopsy (rEBUS-TBCB). A 44-year-old male was admitted to the hospital with a persistent cough and expectoration of bloody sputum for over 6 months. Thoracic computed tomography revealed widespread cystic lesions and nodules. Despite multiple misdiagnoses, rEBUS-TBCB successfully confirmed the presence of lung adenocarcinoma and identified an echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) E13:A20 gene rearrangement. The patient was subsequently transferred to a local hospital for oral targeted drug therapy, which resulted in a favorable response.

CONCLUSION: In conclusions, transbronchial lung biopsies often provide inadequate specimens for confirming diffuse cystic lung diseases. In contrast, the utilization of rEBUS-guided TBCB offers superior diagnostic capabilities, as it enables the collection of larger lung biopsies with higher diagnostic yields and fewer complications compared to surgical lung biopsy.