Primary spinal intramedullary Ewing-like sarcoma harboring CIC - DUX4 translocation: a similar cytological appearance as its soft tissue counterpart but no lobulation in association with desmoplastic stroma

We report a rare case of primary spinal intramedullary Ewing-like sarcoma harboringCIC-DUX4 translocation. A 23-year-old man presented with weakness in the extremities. Magnetic resonance imaging revealed a large intramedullary tumor spanning C3 –C5 with heterogeneous enhancement following gadolinium administration. Histologically, most of the tumor displayed dense myeloid proliferation composed of medium- to slightly small-sized primitive cells. Postoperatively, he received local adjuvant radiation therapy without tumor progression for 1 0 months. Target RNA sequencing analysis revealed theCIC-DUX4 fusion gene. Methylation array analysis resulted in a diagnosis of “methylation class CNS Ewing sarcoma family tumor withCIC alteration ”. Although this tumor lacked characteristic histological features such as lobular structures in association with desmoplastic stroma, relatively uniform nuclei with prominent nucleoli and eosinophilic cytoplasm, which are often found inCIC-rearranged sarcomas of soft tissue, were identified. Recently, many CNS and soft tissue tumors require genetic analysis for precise diagnosis. To consider certain molecular testing, careful histological examination is essential.

Source: Brain Tumor Pathology - May 23, 2020 Category: Neurology Source Type: research