Rationale and objectives: We evaluated pathologic correlations of pulmonary parenchymal manifestations surrounding small peripheral masses and their usefulness in differentiating small peripheral bronchogenic carcinomas from tuberculomas.
Methods: We evaluated 29 resected lobe specimens with 1.5- to 3.5-cm solitary pulmonary masses, including 24 carcinomas and five tuberculomas. These specimens were prospectively studied with preoperative chest radiographs, postoperative specimen radiographs, 10- to 15-microns-thick wholemount sections, and 5-microns-thick slices. A total of 100 chest X-rays and conventional tomography scans of 1- to 3-cm peripheral pulmonary masses, including 60 carcinomas and 40 tuberculomas, were retrospectively reviewed and analyzed.
Results: The pulmonary parenchymal manifestations surrounding the masses presented as small infiltrates and nodular protrusions, thickened strands, and "double track" shadows, which extended from the proximal margin of five tuberculomas (100%, 5 of 5) and from the distal margin of 17 carcinomas (71%, 17 of 24). These pulmonary changes represented caseous material spreading from tuberculomas into the proximal bronchus and alveolar inflammatory exudation distal to the carcinomas. The proximal pulmonary manifestations were significantly more frequent in tuberculomas than in carcinomas (p < .01), whereas the distal pulmonary manifestations were more often found in carcinomas than in tuberculomas (p < .01).
Conclusion: The radiologic findings of the pulmonary parenchymal manifestations proximal or distal to the masses may be valuable radiologic signs for distinguishing between tuberculomas and small peripheral bronchogenic carcinomas, even though there is still considerable crossover between the two disease populations in the findings.