Surgical debulking with fertility preservation in primary extra-neural ependymoma presenting with widespread peritoneal and intra-abdominal disease: Case report and literature review

Background: Extra-neural ependymoma is an extremely rare neoplasm with reported cases arising from the ovary, pelvis, broad and uterosacral ligaments, peritoneum and mediastinum. Case Presentation: A 29-year-old woman presented with abdominal pain. Computed tomography demonstrated bilateral adnexal masses, omental and peritoneal nodules and a 140 mm left upper quadrant mass. FDG PET/CT showed avid, disseminated abdominal disease. CA125 was 265. Differential diagnoses included tubo-ovarian malignancy, peritoneal carcinomatosis, and mesenchymal tumours. Diagnostic laparoscopy with biopsy established Stage IV extra-neural ependymoma based on histological features, immunophenotype and the absence of central nervous system disease on magnetic resonance imaging. She underwent primary cytoreduction including en bloc hysterectomy with ultra-low anterior resection, right salpingoophorectomy, left salpingectomy, peritonectomy, splenectomy with en-bloc partial resection of the left hemi-diaphragm and loop ileostomy. Intraoperatively, the right ovary was utilised for ex-vivo in-vitro oocyte maturation, and the left ovary was conserved for oocyte retrieval and cryopreservation for future surrogacy. Adjuvant chemotherapy was recommended but declined. She remained well at eleven months post-operatively. Conclusion: Extra-neural ependymomas are exceedingly rare with five reported cases of peritoneal ependymoma. Extra-neural ependymomas demonstrate distinct histological and immunophenotypic profiles including increased architectural variability within the spindled cell perivascular pseudorosettes characteristic of ependymomas and diffuse ER and PR positivity. Given limited evidence, optimal management remains undefined however surgical cytoreduction continues to be the cornerstone of management across reported cases with adjuvant treatment individualised. Certain fertility preservation strategies are concurrently feasible within a multidisciplinary framework and should be considered given reported cases are predominantly seen in younger females.