Myxopapillary ependymoma with anaplastic features: A case report with review of the literature

Abstract

Background: Myxopapillary ependymoma (MPE) with anaplastic features is extremely rare, with only three case reports in the literature.

Case description: We report the case of a MPE with anaplastic features in a 24-year-old female who presented with a dominant lumbar mass along with intracranial and sacral metastases. Upon gross total resection of the dominant tumor located at L2-L3, it appeared to arise from the filum terminale, and had a solid component in addition to soft or necrotic areas. Histologically, the tumor was composed of the two classic components of MPE: (1) low-grade ependymal cells surrounding blood vessels, producing the papillary appearance and (2) perivascular myxoid material between blood vessels and ependymal cells, creating the myxopapillary appearance. The high-grade anaplastic component showed hypercellularity, brisk mitotic rate, and vascular proliferation, with frequent pleomorphic cells and atypical mitotic figures. It was positive for vimentin and glial fibrillary acidic protein (GFAP); negative for epithelial membrane antigen (EMA), CAM5.2, creatine kinase 7 (CK7), CK20; and the MIB-1 index (Ki-67) was 8-38%. Ten months after initial resection, follow-up magnetic resonance imaging revealed new lesions in (1) the hypothalamus, (2) the left pons, and (3) the left medial temporal lobe, which were treated with radiosurgery. Eight months later (18 months from initial surgery), the patient underwent thoracic laminectomy for a large leptomeningeal metastasis at T6 and T8.

Conclusion: The present case of MPE with anaplastic features is the fourth case on record in the medical literature.

Keywords: Anaplastic ependymoma; myxopapillary ependymoma; myxopapillary ependymoma with anaplastic features.

Figure 1

(a) Contrast enhanced sagittal T1-weighted magnetic resonance imaging demonstrates a homogeneously enhancing mass centered on L2-3 as well as a small sacra drop metastasis in the sacrum (arrowhead). Axial T1 contrast enhanced MRI demonstrates bilateral enhancement in the internal auditory canals, and a small enhancing focus was identified in the region of the left tectum (panels b and c, respectively)

Figure 2

Low magnification view (panel a) demonstrating typical low-grade myxopapillary ependymoma including papillary appearance and fibrovascular cores. Other areas of tumor (panel b, shown under high magnification) demonstrate anaplasia and cellular atypia typical of high-grade tumor. Tumor specimen was diffusely positive for GFAP staining, indicating a neuronal differentiation, and demonstrated a high Ki-67 index (panels c and d, respectively)

Figure 3

Axial and sagittal contrast enhanced T1-weighted MRI showing large enhancing mass within the thoracic spine causing compression of the thoracic spinal cord (a and b, respectively). Postoperative sagittal MRI demonstrates gross total resection of enhancing mass (panel c) MRI, magnetic resonance imaging