AbstractBackgroundWe report the clinicopathological characteristics, immunohistochemical features, ultrastructure, tissue source, differential diagnosis, treatment, and prognosis of a patient with a uterine tumor resembling ovarian sex-cord tumor (UTROSCT).Case reportA 40-year-old woman had a uterine myoma with enlargement for 2.5 years. An ultrasound examination showed a mixed echogenic mass at the posterior wall of the uterus and a dark cyst in the right adnexal area, which suggested a suspected uterine myoma with liquefaction and a suspected chocolate cyst. The patient underwent transabdominal tumor resection with removal of the right adnexal mass. Through postoperative pathological examination, the patient was diagnosed with UTROSCT. No recurrence was observed after a follow-up of 1 year.ConclusionAlthough UTROSCT is usually benign, it can relapse or metastasize, and patients with UTROSCT need comprehensive diagnosis and treatment.