Solitary Lung Cavities on CT Imaging: Differentiating Malignant and Non-Malignant Diseases

Background This study aims to explore how radiological findings contribute to distinguishing between benign and malignant diseases in patients with solitary cavitary lesions detected on CT. Methods We retrospectively assessed lesion size, cavity wall thickness, and additional parenchymal findings in diagnosing benign or malignant disease in these patients. Our study investigated the incidence and etiology of solitary pulmonary cavities. CT scans were reviewed by a single radiologist with expertise in thoracic radiology. The study was conducted using two 64-multidetector CT systems, and measurements of lesion size and cavity wall thickness were recorded on axial images. Consolidation and centrilobular nodules were assessed based on predefined criteria. Receiver operating characteristic curves were generated to determine optimal cut-off points for distinguishing between malignant and non-malignant lesions based on cavity wall thickness. Results Non-malignant lesions accounted for 47.9% of cases, with active pulmonary tuberculosis being the most common diagnosis. In the malignant group, primary lung cancer predominated, squamous cell carcinoma being the most prevalent subtypes. Significant differences were noted between malignant and non-malignant cases regarding average maximum wall thickness and lesion diameter. Presence of perilesional consolidation or centrilobular nodules favored non-malignant diagnoses. Maximum wall thickness thresholds of 7.2 mm or 23 mm were most accurate in suggesting non-malignant and malignant etiologies, respectively. Conclusions In conclusion, CT findings revealed significant distinctions between malignant and non-malignant solitary lung cavities; benign lesions generally exhibited smaller and thinner cavity walls, with accompanying perilesional parenchymal findings observed in benign lesions of infectious origin but not in malignant lesions.