Inoue D, Zen Y, Komori T, et al. - Via a total of 31 paravertebral lesions identified in 30 patients, researchers characterized the CT findings of IgG4-related paravertebral lesions. All lesions were located around thoracic vertebrae, especially the lower thoracic regions. Twenty-six lesions included two or more vertebrae in a row. In all cases except one, the right side of vertebrae was predominantly influenced. Radiologically, the paravertebral lesions were distinguished as a bandlike, demarcated soft-tissue mass (mean maximum thickness, 8.7 mm) with homogeneous enhancement on late-phase images of contrast-enhanced CT. At other sites, all patients had IgG4-related lesions. Histologically, paravertebral lesions exhibited sclerosing inflammation comprising of diffuse lymphoplasmacytic infiltrations with many IgG4-positive plasma cells and irregular fibrosis. In conclusion, IgG4-related paravertebral lesions occur mainly in the right side of the lower thoracic vertebrae and manifest as a homogeneously intensified bandlike mass corresponding to plasma cell-rich sclerosing inflammation.