Metastatic thoracic and lumbar intramedullary and extramedullary Ewing's sarcoma: a rare case report and literature review

Abstract

Ewing sarcoma (ES) is a highly aggressive bone and soft tissue tumor that occurs mainly in young children and adolescents and is associated with primary and metastatic disease. Intramedullary ES (either primary or secondary) is rare, and the ideal management remains inconclusive. We herein report intramedullary and extramedullary metastatic ES in a single patient. A 46-year-old woman was referred to our outpatient clinic from the oncology clinic with progressive paraparesis and paresthesia for 1 week prior to presentation. She had developed left clavicular ES 2 years earlier for which surgery and chemoradiotherapy had been performed. At the present evaluation, she was diagnosed with intramedullary thoracic and lumbar extradural masses. Thoracic surgery was performed, and a biopsy of the lesion was obtained. The diagnosis of ES was confirmed histopathologically, and she underwent adjuvant chemotherapy. Her neurological status did not improve after surgery, and she underwent rehabilitation and physical therapy. The lumbar lesion resolved with chemotherapy. Metastasis of ES to the spinal cord, especially intramedullary lesions, is extremely rare, and there is no standard management guideline. However, surgical decompression and adjuvant chemotherapy are the main treatments in these cases.

Keywords: Ewing sarcoma; adjuvant chemotherapy; extramedullary; intramedullary; metastasis; rare; surgical resection.

Figure 1.

Sagittal T2-weighted MRI of the patient demonstrating an intramedullary lesion extending from T5 to T8 with hyperintense signals associated with increased spinal cord diameter (a) with scattered enhancement after gadolinium injection (b). Sagittal T2-weighted MRI of the lumbosacral spine showing a round intradural extramedullary isointense lesion compressing the conus medullaris (c) with homogenous enhancement after gadolinium injection. MRI, magnetic resonance imaging.

Figure 2.

Postoperative sagittal T2-weighted cervicothoracic MR image of the patient showing an intramedullary lesion extending from T5 to T8 with hyperintense signals (a). Postoperative T-1 weighted MR image with gadolinium enhancement showing the lesion after internal resection and decompression (b). Post-chemotherapy T2-weighted MR image of the lumbosacral spine showing complete resolution of the extradural lesion (c). MR, magnetic resonance.

Figure 3.

(a) Histopathological sections showing sheets of small round cells with moderate pleomorphism, nuclear atypia, and some true rosette formations (arrows) in a pauci-vascular background (×400, H&E) and (b–d) Immunohistochemical staining of the tumor showing diffuse, strong immunoreactivity for CD99, and a high proliferative index (Ki-67) with negative staining for LCA (×100, ×100, ×40; b–d, respectively). H&E, hematoxylin and eosin; CD99, cluster of differentiation 99; LCA, leukocyte common antigen.