Neoplasms arising within pulmonary cystic airspaces are rare and diagnostically challenging entities that frequently lead to delayed recognition and advanced disease at diagnosis. We report the case of a 61-year-old smoker who presented with significant weight loss and two cystic pulmonary lesions on chest computed tomography (CT). An initial CT-guided transthoracic biopsy was non-diagnostic, and the patient subsequently underwent imaging surveillance. Follow-up CT demonstrated interval growth, progressive wall thickening, and spiculated margins, while ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) showed intense metabolic uptake, raising a strong suspicion for malignancy. Subsequent bronchoscopy with radial endobronchial ultrasound (r-EBUS) enabled real-time localization and transbronchial sampling of the lesion, confirming pulmonary adenocarcinoma. This case highlights the importance of maintaining a high index of suspicion for malignancy in cystic lung lesions, particularly in high-risk patients, and underscores the diagnostic value of r-EBUS as a safe, minimally invasive approach when conventional biopsy techniques are non-diagnostic.
Almeida et al. (Mon,) studied this question.