Abstract
BACKGROUND: Metastatic low-grade endometrial stromal sarcoma (LG-ESS) with sex cord-like and smooth muscle-like differentiation is rare. This article reports such a case with multiple recurrences and with extensive pelvic and abdominal metastasis. CASE SUMMARY: A 47-year-old female patient was diagnosed with multiple cystic masses in the pelvic cavity by magnetic resonance imaging examination. Based on the postoperative pathological and immunohistochemical analyses of the surgical specimen, she was diagnosed with a metastatic low-grade endometrial stromal sarcoma with sex cord and smooth muscle differentiation. CONCLUSION: LG-ESS is a low-grade malignant tumor with a high recurrence rate and metastasis probability. It is easily misdiagnosed initially. It is essential to distinguish LG-ESS with sex cord-like differentiation from uterine tumour resembling ovarian sex cord tumour.