Primary clear cell sarcoma of soft tissue in the posterior cervical spine invading the medulla oblongata: A case report

Figure 1 Computed tomography angiography images showing a posterior cervical soft tissue mass. A: Plain scanning (axial view) showed a left paravertebral soft tissue mass at 1-2 levels in the neck, with clear boundaries; B: Enhanced scanning (coronal view) showed a mass protruding into the spinal canal of the cranio-cervical junction through the foramen magnum; C: Enhanced scanning (sagittal view) showed that the supplying artery was tortuous.

Figure 2 Magnetic resonance imaging of the neck. A: Iso-signal on axial T₁-weighted image; B: Slightly higher signal on sagittal T₂-weighted image (T₂WI); C: Significantly high signal on diffusion weighted imaging; D: Invasion of the anterior medulla oblongata with obvious uneven enhancement; E: The protrusion of the mass locally compressed the cervical spinal cord on T₂WI.

Figure 3 Histopathological and genetic images. A: Oval tumor cells are separated by fibrous tissue in nests or bundles, which show atypical mitosis (hematoxylin and eosin staining, × 400); B and C: Immunohistochemical staining revealed positivity for S-100 (B) and HMB45 positive (C) (× 400); D: Fluorescence in situ hybridization revealed 54% of positive cells in a total of 100 tumor cells, indicating EWSR1 gene break.