Introduction: The detection of solitary pulmonary nodules (SPNs) has increased due to widespread use of computed tomography; nevertheless, chest radiographs still remain the basic routine examination. The aim of the study was to estimate the detection of SPNs in routine chest X-rays in hospitalized patients and to assess the incidence of malignancy in newly diagnosed SPNs.
Material and methods: We analyzed 5,726 routine chest radiographs of patients admitted to the Department of Internal Diseases, Pneumology and Allergology in 2004 and 2005. Most of the patients were admitted to hospital due to emergency reasons. The malignant nature of the nodules was confirmed by pathological examination. The nature of benign nodules was confirmed either by pathological examination or based on radiological criteria: no growth within 2 years of radiological follow up, regression in control radiograms or CT scans, benign pattern of calcification.
Results: Among the 5,726 radiograms we found 116 newly diagnosed SPNs (2.2%). Twenty-four nodules (21%) were malignant: NSCLC in 21 cases and metastases in 3 cases. Fifty-one nodules (44%) were benign. In 19 patients (16%) SPNs proved to be artefacts or erroneously interpreted extrathoracic lesions. In 22 cases (19%) there was no final diagnosis (lack of data, diagnostic procedure renunciation).
Conclusion: The incidence of newly detected SPNs in chest X-rays was 2.2%. Most SPNs were benign. About 21% of SPNs were diagnosed as malignant.