Peripheral-type primitive neuroectodermal tumor of the ovary with EWSR1–FLI1 fusion transcript: a case report and brief review of literature

Primitive neuroectodermal tumors (PNETs) of the ovary are extremely rare tumors composed of undifferentiated small cells with round nuclei and scant cytoplasm. They are rare in general and extremely rare in the female gynecological tract, where they most commonly affect the ovary, followed by the uterine corpus. The most common presenting symptoms are abdominal pain, bloating and the presence of a pelvic mass. Diagnosis mainly relies on immunohistochemical and fluorescence in situ hybridization (FISH). Due to the rarity of these tumors, there are no standard therapeutic guidelines and treatment consists of surgery, various chemotherapy regimens and/or radiotherapy. In this article, we report the case of a 30-year-old female with peripheral-type PNET (pPNET) of the ovary featuring Ewing sarcoma breakpoint region 1–Friend leukemia integration 1 (EWSR1–FLI1) fusion transcript, confirmed by next-generation sequencing (NGS).