case_images: PMC6195912_01
case_images: MRI of a 49-year-old female with pigmented villonodular synovitis of the cervical spine. (a) Axial T
  1 weighted imaging without intravenous contrast demonstrates a heterogeneously hypointense trans-spatial mass (white open arrows) involving the dens and right lateral mass of C2, the anterior arch and right lateral mass of C1, and the prevertebral space. (b) The mass is markedly hypointense on T
  2 weighted imaging. (c) On sagittal contrast-enhanced fat-suppressed T
  1 weighted image, the lesion demonstrates faint, heterogeneous enhancement. There is no epidural extension of tumour.
case_images: bjrcr.20150264.g001.jpg
case_images: PMC6195912_01_bjrcr.20150264.g001.jpg
case_images: f1
case_images: C2, the anterior arch and right lateral mass of C1, and the prevertebral component of the perivertebral space (Figure 1). Contrast-enhanced CT (CECT) revealed a soft-tissue density, lytic lesion with a sharp zone of transition and sclerotic margins (Figure 2).
case_images: CT imaging of a 49-year-old female with pigmented villonodular synovitis of the cervical spine. (a) A contrast-enhanced CT scan reveals a lytic, heterogeneously enhancing, soft-tissue density mass (black solid arrow) involving the C1 and C2, extending ventrally into the prevertebral component of the perivertebral space (black open arrow). The anterior displacement of the right parapharyngeal space is noteworthy (black arrowhead), as expected from a mass originating in the prevertebral space. (b) Axial bone algorithm NECT demonstrates the lytic lesion (white solid arrow) involving the C1 and C2, including its involvement of the dens (white arrowhead). The sharp zone of transition and thin, sclerotic margins are noteworthy features typically associated with benign, slow-growing lesions. No matrix mineralization is seen. (c) Coronal reconstruction of bone algorithm NECT clearly demonstrates that the lesion is centred about the atlantoaxial joint (white open arrow), a critical diagnostic feature establishing this to be a tumour of synovial origin. NECT, non-contrast-enhanced CT.
case_images: bjrcr.20150264.g002.jpg
case_images: PMC6195912_01_bjrcr.20150264.g002.jpg
case_images: f2
case_images: C2, the anterior arch and right lateral mass of C1, and the prevertebral component of the perivertebral space (Figure 1). Contrast-enhanced CT (CECT) revealed a soft-tissue density, lytic lesion with a sharp zone of transition and sclerotic margins (Figure 2). Critical to establishing the diagnosis, the non-contrast-enhanced CT demonstrated the lesion to be centred about the atlantoaxial joint (Figure 2).
case_images: FDG-PET/CT imaging of a 49-year-old female with pigmented villonodular synovitis of the cervical spine. (a) Fused axial FDG-PET/CT image demonstrates the cervical spine lesion to be markedly FDG avid. (b) Coronal FDG-PET image demonstrates the C1/C2 lesion (white solid arrow), but there are no other suspicious foci of FDG uptake. Although seen with malignancy, FDG avidity is a marker of metabolic activity and is a non-specific finding that can also be seen with infectious, inflammatory and metabolic lesions. FDG, fludeoxyglucose; PET, positron emission tomography.
case_images: bjrcr.20150264.g003.jpg
case_images: PMC6195912_01_bjrcr.20150264.g003.jpg
case_images: f3
case_images: Whole-body FDG-positron emission tomography (PET)/CT was performed (Figure 3), revealing the mass to be markedly FDG avid with a maximum standardized uptake value of 24.53.