case_images: PMC7568114_01
case_images: (a) Lateral cervical spine X-ray shows an exostosis at the posterior part of the craniovertebral junction (white arrow). (b) Sagittal T2 WI MRI shows a bony spur from the lip of the foramen magnum (white arrow) pressing on the spinal cord and causing signal changes.
case_images: SNI-11-296-g001.jpg
case_images: PMC7568114_01_SNI-11-296-g001.jpg
case_images: F1
case_images: Plain X-ray of the cervical spine [Figure 1] showed an exostosis at the posterior aspect of the craniovertebral junction; this finding was confirmed on CT scan [Figure 2].
case_images: Axial CT scan shows the osteochondroma protruding into the cervical canal (white arrow), (a) axial view of foramen magnum, (b) axial view C1.
case_images: SNI-11-296-g002.jpg
case_images: PMC7568114_01_SNI-11-296-g002.jpg
case_images: F2
case_images: Plain X-ray of the cervical spine [Figure 1] showed an exostosis at the posterior aspect of the craniovertebral junction; this finding was confirmed on CT scan [Figure 2].
case_images: (a) Intraoperative photograph after removing the posterior arch of C1 lamina shows the pointer identifying the tip of the exostosis arising from the posterior lip of the foramen magnum. (b) Intraoperative photograph after removing the osteochondroma shows the decompressed cervical spinal cord.
case_images: SNI-11-296-g003.jpg
case_images: PMC7568114_01_SNI-11-296-g003.jpg
case_images: F3
case_images: The cervical MR showed severe cord compression from the posteriorly located exostosis, and there was a high signal in the cord on the T2-weighted image [Figure 3]. The patient underwent removal of the C1 lamina en bloc laminectomy; it revealed a bony exostosis covered with a cartilaginous cap arising from the posterior lip of the foramen magnum that was drilled away achieving good decompression of the dura surrounding the spinal cord [Figure 3a and b].
case_images: Microscopic histology of the osteochondroma lesion sample during the procedure, (a) the perichondrium, (b) the cartilage cap.
case_images: SNI-11-296-g004.jpg
case_images: PMC7568114_01_SNI-11-296-g004.jpg
case_images: F4
case_images: The histopathological report confirmed the diagnosis of osteochondroma [Figures 4].