[Radiologic projection on the sagittal plane as a diagnostic parameter in primary lung neoplasms]

A study was carried out to evaluate the importance of location of radiological densities on lateral protection of X-ray films of the chest, as a valuable sign for the clinical diagnosis of primary neoplasms of the lung. Clinical case records of 100 patients with pneumonitis, 61 patients with active pulmonary tuberculosis and 58 cases with primary pulmonary neoplasms -- in which diagnosis was verified by hystological examination of biopsies performed during bronchoscopy or by autoptic control -- were reviewed. Radiological location in anterior or central-anterior planes was observed in only 14 per cent of patients with pneumonitis while in 86 per cent the location was in posterior or central-posterior planes. Only 10 per cent of patients with active pulmonary tuberculosis had their densities situated on anterior or central-anterior planes of the chest X-ray while in the remaining 90 per cent of cases the location was in central-posterior or posterior planes of the radiogram. In 74 per cent of patients with primary lung neoplasms we observed that radiological densities were located in the anterior or central-anterior planes; only in 26 per cent of patients the radiological location was in the posterior or central-posterior planes. Since in most instances of primary lung neoplasms the initial diagnostic approach is roentgenographic, it seems of particular importance in differential diagnosis to consider as neoplastic those lesions located in the anterior planes of an X-ray film taken in lateral projection until proven otherwise. This radiological aspect implies the opportunity to perform a bronchoscopic and hystological evaluation even in those patients in which clinical aspects should seem less suggestive of primary lung neoplasm. A posterior location does not exclude -- according to our data -- the neoplastic origin of a density but this radiological criterion does seem to justify a less aggressive diagnostic approach in all those patients which present contraindications or refuse invasive procedures.