Extraosseal Ewing sarcoma as a rare cause of the blueberry muffin baby syndrome: a case report and the review of the literature

Abstract

The blueberry muffin baby syndrome can be caused by a variety of entities, both neoplastic and nonneoplastic. We present a rare cause of this syndrome: congenital extraosseal Ewing sarcoma. The patient was a blueberry muffin baby with a retroperitoneal tumor, whose cells were negative for neuronal markers and CD-99 immunohistochemically but were positive for a breakpoint in EWSR1 gene. This tumor could be one of the most primitive/undifferentiated examples in the Ewing/peripheral primitive neuroectodermal tumor family.