Imaging Features of Solitary Plasmacytoma of Bones

Objective To improve diagnostic ability by analyzing the imaging features of X-ray, CT and MRI for solitary plasmacytoma occurred in different sites of bones. Methods We retrospectively reviewed twelve pathologically proven cases of solitary plasmacytoma that existed on centrums, shoulder bones and ribs, and summarized their imaging features. Results The prevalence bones were the rib (n=3), thoracic vertebra (n=6), and the shoulder bone (n=3). Of those, pathological fracture had one case on shoulder bone. X-ray and CT showed osteolytic destruction and expansive growth with relative clear border. Periosteal reaction was not observed in all cases, although one case had cortical bone thickening, hardening.Solitary plasmacytoma showed homogeneous slight hypo-intensity on T1-weighted MR images and hyper-intensity on T2-weighted MR images compared to muscle. Peritumoral edema was not observed in all the cases, but soft-tissue invasion in various degree was clear and soft-tissue mass was apparent in five cases with enhanced contrast. Conclusion X-ray was lower sensitive for solitary plasmacytoma in bones; CT could clearly show the thickening trabecula and residual bone in the tumor; MRI could show the relationship between exterior and interior pathological of medullary cavity and surrounding soft tissue. Combination of radiography, CT and MR imaging might improve diagnosis.