Sinonasal FUS-ERG-Rearranged Ewing ’s Sarcoma Mimicking Glomangiopericytoma

Ewing ’s sarcoma is a rare and aggressive tumor that typically arises in the long bones of the extremities. It belongs in the family of small round blue cell tumors and is characterized immunohistochemically by diffuse CD99 expression and molecularly by one of several oncogenic translocations, most comm only t(11;22)(q24;q12) between theEWSR1 gene and theFLI1 gene. Here we present a rare case of Ewing ’s sarcoma in the sinonasal tract withFUS-ERG gene arrangement that was regarded for almost a decade as a sinonasal-type hemangiopericytoma (glomangiopericytoma). This case illustrates the surprisingly prolonged natural history of Ewing ’s sarcoma that did not receive therapy for many years and the importance of considering alternative genetic translocations. Our experience suggests that the presence of diffuse CD99 membranous staining pattern in a small blue round cell tumor with morphology typical for Ewing’s sarcoma but FISH negative forEWSR1 rearrangement should prompt consideration ofFUS-ERG fusion.Case Rep Oncol 2020;13:1393 –1396
Source: Case Reports in Oncology - Category: Cancer & Oncology Source Type: research