High-grade Endometrial Stromal Sarcoma With BCOR Gene Alterations is Recommended as an Independent Subtype of Endometrial Carcinoma: A Case Report

Background: The uterine leiomyosarcoma combined high-grade endometrial stromal sarcoma (HGESS) with BCOR gene alterations is exceedingly rare. The subtype of YWHAE-FAM22 HGESS is shown in the current World Health Organization classification, but not HGESS with BCOR alterations. Case presentation: We reported such a case in which HGESS with BCOR gene alterations and leiomyosarcoma coexist in a patient. And, most impressively, HGESS with BCOR gene alterations caused ovarian and pelvic metastases, although its volume was less than 1% of leiomyosarcoma. Conclusions: : Given the more aggressive of HGESS with BCOR gene alterations, we suggest that it is classified as an independent subtype of HGESS, and when it coexists with other types of tumors, the HGESS with BCOR gene alterations needs to be noted in the pathological report even if it accounts for less than 1% of the tumour mass.