PMC5369253_01
Preoperative images. (a) Axial CT scan showing a left osteolytic occipital lesion surrounded by sclerotic tissue extended inferiorly up to the foramen magnum. (b and c) 3D reconstructions of the CT angiogram illustrating the close relationship between the tumor and the vertebral and occipital arteries. (d) Sagittal post-contrast T1-weighted MRI scan revealing an avidly enhancing occipital extra-axial mass
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F1
In addition, the CT angiography with three-dimensional (3D) reconstruction revealed a close relation between the tumor and the vertebral and occipital arteries [Figure 1]. Eventually, a craniocervical magnetic resonance imaging (MRI) showed the soft extracranial tissues partially affected by the tumor, without intracranial extension [Figure 1].
Intraoperative photographs. (a) Initial removal of the lesion with a high speed drill. (b) Removal of the lesion using a kerrison rongeur, once the dura is reached, in order to prevent inadvertent dural lacerations. (c) Surgical field at the end of the resection with the surrounding normal bone
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F2
However, the left occipital condyle was left undisturbed [Figure 2; Video 1] (Supplemental Digital Content, illustrating the microsurgical removal of the lesion).
Post-operative images. (a) Axial CT scan showing the lesion was totally removed. (b and c) 3D CT scan reconstructions illustrating the reconstruction of the skull defect with a titanium mesh
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F3
The histopathological examination was consistent with benign osteoblastoma, and the postoperative CT scan showed the complete resection of the lesion [Figure 3].