Radiological Case

Rib Osteochondromas Mimicking Lung Nodules

Gali Shapira-Zaltsberg, MD; Carmen Rotaru, MD


Appl Radiol. 2021;50(1):56a-56b. 

In This Article

Imaging Findings

A chest radiograph (Figure 1) revealed two nodules projecting over the left upper lung field and one larger nodule projecting over the left middle lung field. A thin linear density could be appreciated, extending laterally from the larger nodule. The lungs were otherwise clear. The pleural spaces were clear. The mediastinal contour and cardiac silhouette appeared within normal limits. There was a small suspected exostosis off of the right posterior third rib and an exostosis noted off of the right scapula.

Figure 1.

PA radiograph of the chest shows multiple nodular opacities projecting over the left lung, concerning for pulmonary nodules.

A subsequent contrast-enhanced CT performed to further assess the suspected pulmonary nodules revealed multiple bony exostoses arising from all the ribs, the vertebrae included in the scan, and the clavicles, as well as the scapula, sternum, and proximal humeri. A calcified structure measuring approximately 2.4 × 1.8 × 1.6 cm was centered in the left pulmonary fissure with a long, thin stalk extending laterally within this fissure to the lateral aspect of the left fifth rib (Figure 2). This lesion corresponded to the largest apparent "lung nodule" on chest X-ray. An additional calcified structure with a lobulated appearance measuring approximately 3.0 × 1.8 × 2.0 cm was seen arising from the anterior aspect of the left second rib (Figure 2). This lobulated structure likely accounted for the additional nodules projecting over the left upper lung on the chest X-ray. Given that the patient's chest pain was on the contralateral side, the large osteochondromas described here were likely asymptomatic at this stage.

Figure 2.

Sagittal (A) and axial (B) CT images reveal an osteochondroma with a long stalk extending within the left pulmonary fissure.