A 29-year-old man presents with abdominal pain and is found to have a 5 cm presacral mass and vertebral metastasis.
The correct answer is ...
The correct answer is: EWSR1-FLI1 fusion.
The histologic sections show a monotonous, small, round, blue cell neoplasm that is characteristic of Ewing’s sarcoma. The most common genetic alteration of Ewing’s sarcoma is EWSR1-FLI1 gene fusion, although alternative fusions between FET family genes and genes encoding for ETS-transcription factors have been described. The SS18-SSX1 gene fusion is found in synovial sarcoma. BRAF v600e mutations are found in a multitude of malignancies, including melanoma and papillary thyroid carcinoma, among others. FUS-DDIT3 gene fusion is found in myxoid liposarcoma.
Jeremy Molligan, M.D.
Senior Associate Consultant, Anatomic Pathology
Jorge Torres-Mora, M.D.
Consultant, Anatomic Pathology
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine and Science