[1804] Malignant Epidural Spinal Cord Tumor with Neuroendocrine Differentiation Associated with EWSR1/ATF1 Fusion Transcript

Carrie A Mohila, Adriana Olar, Angshumoy Roy, Michael D Weindel, Andrew H Jea, Murali Chintagumpala, Dolores Lopez-Terrada, Adekunle M Adesina. Texas Children's Hospital and Baylor College of Medicine, Houston, TX; The Methodist Hospital, Houston, TX

Background: Epidural spinal cord tumors in children are relatively rare. They can arise from bone, dura, or soft tissues and in the pediatric population include neuroblastoma and Ewing's sarcoma among others. We report a case of a previously healthy 10 year old girl who presented with a 10-day history of bilateral lower extremity numbness with episodes of falling. Imaging revealed a large extradural thoracic mass compressing the spinal cord.
Design: Tumor tissue was formalin-fixed and paraffin-embedded. Sections were stained with H&E and a panel of antibodies against multiple antigens. Fluorescence in situ hybridization (FISH) using a break-apart probe specific for EWSR1 and reverse transcription polymerase chain reaction (RT-PCR) using specific primers for EWS/FLI1, EWS/ERG, EWS/ATF1, EWS/CREB1, and EWS/WT1 fusion transcripts were performed on tumor tissue.
Results: Histologic examination revealed a tumor composed of infiltrative malignant epithelioid cells with nodular and organoid arrangements. Tumor cells were immunoreactive for synaptophysin, vimentin, EMA, CD99, and low molecular weight cytokeratin and a subset of sustentacular-like cells were positive for S100. Ultrastructural studies revealed poorly differentiated cells with scattered membrane-bound dense core granules. Together these features showed a poorly differentiated tumor with neuroendocrine features consistent with a malignant paraganglioma. FISH demonstrated an EWSR1 gene rearrangement and RT-PCR detected the presence of a EWSR1/AFT1 fusion transcript.
Conclusions: Once thought to be a tumor-defining molecular signature for clear cell sarcoma, ESWR1/ATF1 transcript has also been described in angiomatoid fibrous histiocytoma. The present case is the first to expand the spectrum of tumors with ESWR1/ATF1 fusion to include malignant tumors with neuroendocrine differentiation.
Category: Neuropathology

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 263, Tuesday Afternoon


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