Intracranial Myxoid Mesenchymal Tumor with EWSR1-ATF1 Fusion

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor that arises primarily in the extremities of young adults. Recurrent gene fusions involving EWSR1 with members of the cAMP response element binding protein (CREB) family have been reported in a diverse group of tumors, including AFH. AFH-like lesions have been reported to occur intracranially and the reported cases show low proliferation indices, frequently have a connection with the dura, and show recurrent EWSR1 rearrangements. These tumors have been termed intracranial myxoid mesenchymal tumor with EWSR1-CREB family gene fusions. A literature search identified 11 reported cases of intracranial AFH-like lesions with an EWSR1 rearrangement. Here, we report a case of intracranial myxoid mesenchymal tumor with an EWSR1-ATF1 fusion in an adult patient, and review the existing literature on this recently described entity.