Stereotactic radiosurgery for the treatment of a distant recurrence of ependymoma on the optic nerve: illustrative case

Abstract

Background: Ependymomas rarely disseminate to other central nervous system areas distant from the original site. Stereotactic radiosurgery (SRS) provides high control rates for recurring ependymomas. The treatment of optic nerve tumors carries high morbidity, but SRS is an acceptable option to manage these cases to reduce risks.

Observations: The authors report the case of a 31-year-old male with a cervical spinal ependymoma who had a disseminated pattern of recurrence including the optic nerve after initial resection of the cervical lesion. The optic nerve tumor was treated with SRS, and the authors discuss the technical aspects of the treatment and its outcomes. At the last follow-up, the optic nerve tumor was controlled with SRS, and visual function was preserved.

Lessons: High-grade ependymomas such as the one in the presented case can have unpredictable patterns of recurrence. SRS provides excellent control of the distant recurring ependymoma with a low complication profile given the location of the tumor in this case.

Keywords: anaplastic ependymoma; optic nerve; stereotactic radiosurgery.

FIG. 1

Presurgical MRI. A: Sagittal T1-weighted sequence. B: Sagittal postcontrast T1-weighted sequence. C: Sagittal T2-weighted sequence. D: Axial postcontrast T1-weighted sequence. The intradural-extramedullary mass measured 09 × 1.7 × 4.3 mm, extending from the C4–5 disc space to the upper C7 vertebral body level.

FIG. 2

Histopathological findings of the tumor. Moderately cellular glial neoplasm (A) composed of fibrillary cells with perivascular arrangements consistent with pseudorosettes (B). In focal hypercellular areas of the tumor, numerous mitotic figures were present (C, arrows). The tumor cells were strongly and diffusely GFAP-immunoreactive (D) and showed intracytoplasmic dot-like EMA immunoreactivity (E). The Ki-67 labeling index (MIB-1) was very high (F, about 40%) in the hypercellular areas of the ependymoma. Hematoxylin and eosin (A–C), original magnifications ×100 (A and D), ×200 (B, F), and ×400 (C and E).

FIG. 3

Follow-up MRI. A: Sagittal postcontrast T1-weighted sequence at 6 years showing a new hyperintense lesion on the T10–11 level, extending through the upper level of T11. B: Axial T2-weighted sequence. C: Sagittal T2-weighted sequence from the last MRI follow-up. D: Axial postcontrast T1-weighted sequence showing a left cerebellar hyperintense heterogeneously enhancing lesion. E: Axial T1-weighted sequence showing an isointense cerebellar lesion.

FIG. 4

Axial T1-weighted MRI sequence (A), postcontrast T1-weighted MRI sequence (B), postcontrast T2-weighted fluid-attenuated inversion recovery (FLAIR) MRI sequence (C) showing a hyperintense lesion of 22 × 6 mm on the left posterior intraorbital and intracanalicular portions of the optic nerve. Three-year follow-up T2-weighted FLAIR MRI (D) that shows control of the tumor.