Multidisciplinary Therapy of Uterine Ewing’s Sarcoma With the Preservation of Uterus and Ovarian Function by Laparoscopy: A Case Report and Literature Review

Primary uterine Ewing's Sarcoma is an extremely rare and aggressive tumor. Due to its rarity, there is no established standard treatment, and most cases involve radical surgery, often compromising fertility and ovarian function. Recent advances in multimodal therapy have introduced fertility-preserving approaches for young patients. An 18-year-old woman visited our hospital for a detailed examination of a 10 cm-sized uterine tumor initially diagnosed as a leiomyoma by MRI. A GnRH agonist was administered to treat presumed myoma and associated anemia. Despite the administration of three cycles of the GnRH agonist, the patient's anemia did not improve. The size of the tumor was not reduced, and the inner structure of the tumor became irregular. A tumorectomy was performed and the uterus was repaired. Histological examination, including immunohistochemical staining, suggested Ewing's Sarcoma based on hematoxylin-eosin findings and strong CD99 positivity. Fluorescence in situ hybridization confirmed ESWR1 gene rearrangement in the tumor cells, leading to a definitive diagnosis of Ewing's Sarcoma. Since PET-CT showed pelvic and para-aortic lymph metastasis after laparotomy, VDC-IE chemotherapy was performed after oocyte cryopreservation. The multiple swellings of the lymph nodes were improved. To enhance curative potential, proton therapy was administered to the whole pelvis and para-aortic lymph nodes. To preserve ovarian function, a laparoscopic ovarian transposition was performed before proton therapy. Her right ovary was mobilized to the peritoneum at the level of the upper lobe of the right kidney via a retroperitoneal tunnel. 54-Gy proton therapy was performed, and complete response was obtained. This case of primary uterine Ewing's Sarcoma was treated with multimodal therapy, achieving curative outcome while preserving ovarian function and fertility through laparoscopic ovarian transposition.