Occipital fibrous dysplasia with headaches. 13-year-old male. There is redemonstration of thickening of the left occipital bone with a ground glass appearance consistent with the patient's clinical history of fibrous dysplasia extending from the foramen magnum along its posterior and left lateral aspect and its left lateral aspect of a left occipital condyles and of the left clivus involving the left hypoglossal canal completely and the left the jugular foramen partially. The left condylar canal is also involved. The left hypoglossal canal is a little bit smaller than the right. The right hypoglossal canal measures 3.5 mm in diameter. The left and measures 2.9 mm in diameter. Along the midline the bidimensional measures of fibrous dysplasia of the occipital bone measures at 28 x 68 mm on sagittal imaging. There is an MRI from 9/4/09 which had sagittal imaging. It appears that dimensions at that time were 28 by 68 mm on sagittal imaging as well. It is not possible to make a fair comparison on the in between the prior CT and the current CT due to differences in slice thickness and angulation on imaging. Overall I get the impression that it is larger on the current versus the prior exam. On the scout image a lateral dimensions are 24 x 63 mm indicating interval growth.There is a 15 x 11 mm in sagittal dimension ground glass appearing lesion within the odontoid process. The rest of the cervical or vertebral bodies are probably normal alignment and height.
1.Large area of ground glass appearance of the occipital bone consistent with fibrous dysplasia as described above with diameters hypoglossal canals as described above. A fair comparison the prior CT scan cannot be made as indicated above I suspect it appears larger in the overall thickness. The left jugular foramen is only partially involved.2.Focus of ground glass appearance of bone at the odontoid process consistent with fibrous dysplasia.