PMC4405892_01
Preoperative examination of the patient. (a) Significant ptosis of left eye at rest. (b) Patient in leftward gaze demonstrating complete abduction deficit of left eye
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F1
Ophthalmologic evaluation confirmed a pupil-sparing partial third nerve palsy and a left sixth nerve palsy [Figure 1].
Initial presentation CT angiography. (a) Sagittal image demonstrating a lytic defect in the clivus (black arrow) and associated soft tissue mass (arrowhead) extending into the prepontine cistern. (b) Axial image demonstrating involvement of the left petroclival synchondrosis (arrow) and compression and anterior displacement of the left cavernous carotid artery (arrowhead). No internal calcified or ossified matrix is demonstrated within the mass
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F2
The mass displaced the basilar and left carotid arteries [Figure 2].
Initial presentation MRI. (a) Axial T2-weighted image demonstrating a lobular mass (arrows) arising from the clivus asymmetric to the left side with primarily T2-weighted hyperintense signal except for a region of T2-weighted signal hypointensity (asterisk). The mass extends into the prepontine cistern and deforms the brainstem, extends into the left cavernous sinus and left Meckel's cave with mass effect on the medial left temporal lobe. (b) Axial T2 gradient echo image demonstrating an area of susceptibility corresponding to the previously noted area of T2-weighted hypointensity (arrow) consistent with internal blood products
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F3
T2-weighted signal with layering suggestive of recent hemorrhage [Figures 3 and 4]. The presence of blooming on a gradient echo sequence was also suggestive of hemorrhage [Figure 3b]. The differential diagnosis of the mass included a chordoma with atypical internal hemorrhage, chondrosarcoma, or metastatic lesion.
Initial presentation MRI. (a) Sagittal T2-weighted image demonstrating the T2 hyperintense mass (asterisk) arising from the clivus and compressing the pons. (b) Sagittal T2-weighted image demonstrating internal layering T2 hypointensity consistent with hemorrhage (asterisk). (c) Sagittal T1-weighted postcontrast image demonstrating peripheral enhancement of the mass (arrow)
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F4
T2-weighted signal with layering suggestive of recent hemorrhage [Figures 3 and 4].
Surgical pathology. (a) Groups and cords of epitheliod cells embedded in a myxoid stroma with characteristic physaliphorous cells (arrows). H&E x400. (b) Chordoma with large areas of hemorrhage. H&E x100. (c) Tumor cells showing diffuse cytoplasmic positivity for cytokeratin with antibodies against AE1/AE3. H&E counterstain x200. (d) Positive membranous staining with antibodies against epithelial membrane antigen. H&E counterstain x200
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F5
This showed a variable degree of vacuolization (physaliphorous cells) [Figure 5a and b]. Immunohistochemically, the tumor cells were strongly positive for cytokeratin [Figure 5c] and S-100 protein. Epithelial membrane antigen was also positive in a membranous pattern [Figure 5d].
Examination at 2-month postoperative outpatient follow-up demonstrating resolution of left ptosis (a) and left sixth nerve palsy (b)
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F6
At 2-month follow-up, the patient had resolution of the partial left third nerve palsy and improvement of his left sixth nerve palsy [Figure 6].