Clinical diagnosis
Case 219
【Progress】
He was introduced to the local municipal hospital where the diagnostic biopsy, neuro-surgery and radiotherapy could supply.
【Discussion】
Malignant multiple vertebra lesions in adult are limited to arise from metastatic bone tumors or multiple myeloma. However, a lesion of skull bone is different, and differential diagnosis is necessary not only because of the treatment choice but also some tumors having the specific image characteristics.
Clivus is one of the parts of skull basal bone between occipital bone and sphenoid bone. Bilateral internal carotid arteries, pons and sphenoid sinus situate adjacent to the clivus. The main tumors arisen from clivus are chordoma and chondrosarcoma (1-5). Others are giant cell tumor, plasmacytoma, metastatic tumor and fibrous dysplasia (6-8). Clivus and sacrum have common tumors appearing. These tumors can occur also in sacrum (9).
Chordoma arises from the remnant of the earliest fetal primitive skeleton called notochord. Following sacrum, clivus is the second most common site for emergence of chordoma (9). Chordoma and chondrosarcoma demonstrate high signal intensity on T2WI and low signal intensity on T1WI (3-5). Diffusion WI depict both tumors as high signal intensity but ADC values are different. The ADC values of chordoma are 1.3 to 1.4, while those of chondrosarcoma are more than 2.0 (bone cyst, ADC values 2.6) (1, 2). ADC values are possibly useful to differentiate chordoma from chondrosarcoma.
Giant cell tumors come from osteoclasts. It usually comes from epiphysis of long bone and includes hemorrhagic components. Then, the signal intensity of the tumor varies. ADC values are reported to be around 1.1 (6).
Plasmacytoma arises from plasma cells and comes often from skull including clivus. Dens cells accumulation induces relatively low signal intensity on T2WI but ADC values are low, approximately 0.8 (1-4).
Fibrous dysplasia usually occur systemically but can occur locally, from clivus. It comes from dysfunction of mineralization of osteoblasts, taking place of fibroblasts proliferation, fibrosis without bone formation. Fibrous dysplasia demonstrates low signal intensity on T2WI and ADC values are approximately 2.0 with diffusion ability of water molecule (7).
In our case, the lesion at clivus demonstrated low signal intensity on T2WI MRI and no high signal intensity on diffusion WI MRI, indicating meaningless to measure ADC values. Of the tumors documented above, fibrous dysplasia might meet the image findings of T2WI.
【Summary】
We presented a seventy three-year-old male for double vision. Our ophthalmologist realized he had right abducent nerve palsy. Brain MRI with T2WI depicted a mass lesion with low signal intensity at clivus. It is borne in mind that multiple vertebral lesions of the spine in adult indicate metastatic tumor or multiple myeloma. The lesions at clivus of basal skull bone are listed below for differential diagnosis: chordoma, chondrosarcoma and giant cell tumor. Then, followed by metastatic tumor and multiple myeloma. ADC values are useful to differentiate chordoma from chondrosarcoma or other tumors: ADC values, 1.4 in chordoma and more than 2.0, 2.3 in chondrosarcoma; 1.1 in giant cell tumor: plasmacytoma or multiple myeloma o.5 to 0.8; fibrous dysplasia 2.0.
【References】
1.Yuh S, et al. Diagnostic Imaging Dilemma of a Clival Lesion and Its Clinical Management Implications. J Neurol Surg. 2014; 75: 177–182.
2.Rodrigues JF, et al. (2017) Differential Diagnosis of Clival Lesions – Literature Review of the Clinical and Radiological Features. Ann Otolaryngol Rhinol 2017; 4: 1200.
3.Chambers KJ, et al Incidence and survival patterns of cranial chordoma in the United States. Laryngoscope. 2014; 124: 1097–1102.
4.Doucet V, et-al. MRI of intracranial chordomas. Extent of tumour and contrast enhancement: criteria for differential diagnosis. Neuroradiology. 1997;39 (8): 571-6.
5.Erdem E, et-al. Comprehensive review of intracranial chordoma. Radiographics. 23 (4): 995-1009.
6.Zhao J, et al. Giant cell tumor of the clivus: A case report and review of the literature. Oncol Lett. 2014 Dec; 8(6): 2782–2786.
7.Zhang T, et al. Calcifying fibrous tumor of the clivus presenting in an adult. Radiol Case Rep. 2019 Jun; 14(6): 771–774.
8.Murphey MD, et-al. From the archives of the AFIP. Primary tumors of the spine: radiologic pathologic correlation. Radiographics. 1996;16 (5): 1131-58.
9.de Bruïne FT, et al. Spinal chordoma: radiologic features in 14 cases. AJR Am J Roentgenol. 1988;150 (4): 861-3.
2021.1.27