Low-grade endometrial stromal sarcoma:a clinicopathological analysis of 40 cases

WANG Ji-yuan; YU Hai-yun; HE Chun-yan; WU Chun-chun; ZHANG Jing; JIN Yu-lan

doi:10.3969/j.issn.1007-8096.2025.04.003

Abstract：Objective To investigate the clinical and pathological features of low-grade endometrial stromal sarcoma(LGESS)in order to enhance the understanding of this rare malignancy.Methods A retrospective analysis was conducted on the clinical and pathological data of 40 patients diagnosed with LGESS.Histological morphology,immunohistochemical expression,and molecular pathological characteristics were reviewed and summarized.Results The patients'ages ranged from 25 to 76 years,with a mean age of 45.5 years and a median age of 45 years.Thirty-seven tumors were located in the uterus,two in the ovaries,and one in the broad ligament.The tumors ranged in size from 2 cm to 12.1 cm,with a grayish-yellow or grayish-white cut surface and a soft texture.Larger tumors exhibited cystic changes.Microscopically,the tumors were composed of uniform spindle cells with a low mitotic index.Twenty patients showed smooth muscle differentiation,while five had sex cord-like differentiation.Immunohistochemistry revealed that most tumor cells expressed CD10(40/40),estrogen receptor(ER,36/40),and progesterone receptor(PR,38/40).Molecular testing was performed on 8 patients,and FISH results showed that 6 patients were positive for JAZF1 gene breakage and 4 patients were positive for PHF1 gene breakage.Sequencing revealed 1 case of JAZF1-SUZ12 and 1 case of EPC1-PHF1 fusion.Conclusion LGESS typically presents with characteristic microscopic features that enable diagnosis through histological morphology and immunohistochemical staining.However,differential diagnosis can be challenging in cases with atypical differentiation or non-specific immunohistochemical expression.Molecular testing is essential for confirming the diagnosis when necessary.