Imaging characteristics of primary rib tumors.

OBJECTIVES

We retrospectively determined imaging characteristics of primary tumors of the ribs in conventional radiography (CR), computed tomography (CT), and magnetic resonance imaging (MRI) to differentiate between benign and malignant lesions.

METHODS

A total of 124 patients with 179 primary tumors of the ribs were included and analyzed for morphologic features in CR, CT, and MRI including localization, tumor size and extension, lytic or sclerotic appearance, and signal characteristics. In addition to epidemiological data, clinical parameters such as comorbidity, tobacco consumption, and local pain symptoms were collected from all patients. The data collected were grouped into subcollectives and statistically analyzed concerning distinctive features between malignant and benign tumors.

RESULTS

The majority of primary tumors of the rib were benign (74%), without significant differences in gender distribution. Lesions in patients with a history of smoking and lesions causing local pain had a higher risk of malignancy. Regarding localization, there was no significant difference between benign and malignant lesions. Primary malignant tumors were larger on average, showed an osteolytic and infiltrative growth pattern, and were associated with pathological fractures more frequently. Sclerotic bone lesions and marginal sclerosis of osteolytic lesions were more common in benign tumors. Contrast enhancement and T1-/T2-weighted MRI signals could not differentiate between malignant and benign lesions.

CONCLUSION

In addition to imaging characteristics that reliably contribute to the assessment of the biological behavior of a primary rib tumor, there are features that overlap in benign and malignant lesions. Radiological assessment of the risk of malignancy of a primary rib tumor seems particularly successful when CR, CT, and MRI are combined and used in conjunction with clinical presentation.