CASE REPORT: We reported a rare case of Ewing Sarcoma in a 62-year-old woman who had an unusual clinical presentation. She had right painless buttock swelling only for a month. Magnetic resonance imaging (MRI) revealed soft tissue sarcoma originated from right gluteal muscle. The diagnosis of Ewing sarcoma (ES) was made in a limited diagnostic material in an initial tru-cut biopsy, followed by an excision supported by immunohistochemistry (IHC) and Fluorescent In-Situ Hybridization (FISH).
DISCUSSION: The purpose of this study is to document ES in an adult woman and its diagnostic challenges in histopathologic perspective.