WSI21-141-Case-42
From MGH Learn Pathology
B. CELLBLOCK, RIGHT TEMPORAMANDIBULAR JOINT: Ewing sarcoma. Note: The final diagnosis is amended from nonspecific neoplasm to Ewing sarcoma as a result of molecular testing showing the EWSR1::FLI1 gene fusion. See separate molecular pathology report.
An immunostain for desmin is also negative, which rules out the unlikely possibility of a rhabdomyosarcoma that has been reported to harbor the same fusion.