High-grade endometrial stromal sarcoma presenting with multiple brain metastases: a case report.

Background: High-grade endometrial stromal sarcoma is a rare and aggressive subtype of uterine sarcoma, characterized by a poor prognosis. While typical initial manifestations include gynecological symptoms such as abnormal vaginal bleeding (for example, postmenopausal bleeding, intermenstrual bleeding, or menorrhagia), abdominal pain, and abdominal distension, an initial presentation involving distant metastases, particularly to the brain, is exceptionally uncommon. This case highlights a highly atypical initial presentation of this rare and challenging disease.

Case presentation: This report details a unique clinical scenario of high-grade endometrial stromal sarcoma in a 58-year-old Japanese woman. She presented with left hemiparesis and unexplained weight loss, leading to the discovery of multiple brain tumors on cranial computed tomography. Following craniotomy and tumor resection, pathology suggested metastatic sarcoma. Positron emission tomography-computed tomography subsequently identified the uterus as the most probable primary site. Despite initial negative endometrial biopsy results, a targeted transabdominal computed tomography-guided biopsy ultimately confirmed the diagnosis of high-grade endometrial stromal sarcoma. Furthermore, detailed imaging and pathological findings raised the intriguing possibility that the high-grade endometrial stromal sarcoma may have originated from pre-existing adenomyosis. Despite initial chemotherapy and Gamma Knife radiosurgery for brain metastases, the patient's condition rapidly deteriorated, leading to her death approximately 4 months after initial presentation, highlighting the aggressive nature and poor prognosis of this disease.

Conclusion: The inherent rarity of high-grade endometrial stromal sarcoma, combined with its highly unusual initial presentation as neurological symptoms, significantly contributed to the diagnostic delay in this case. This report critically underscores the vital importance for clinicians to maintain a high index of suspicion for high-grade endometrial stromal sarcoma in the differential diagnosis of patients presenting with brain metastases, even when typical gynecological complaints are absent.