Lung carcinoma with diffuse cysts repeatedly misdiagnosed as pulmonary infections and lymphoid interstitial...

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

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.

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.