Immune checkpoint inhibition in undifferentiated cervical sarcoma with early pelvic recurrence: a case report.

Background: Undifferentiated cervical sarcoma is an extremely rare and highly aggressive malignant mesenchymal tumor. It is associated with a poor prognosis, limited responsiveness to conventional chemotherapy and radiotherapy, and a lack of standardized treatment strategies. Case presentation: We report a 56-year-old postmenopausal woman who presented with vaginal bleeding and was diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage IIB undifferentiated cervical sarcoma. She underwent a modified laparoscopic radical hysterectomy with bilateral salpingo-oophorectomy, and gross intraoperative findings confirmed parametrial involvement. Postoperatively, she received three cycles of adjuvant chemotherapy. However, two months after surgery, during chemotherapy, she developed vaginal cuff bleeding and pelvic recurrence. Immunohistochemical analysis demonstrated programmed death-ligand 1 (PD-L1) positivity. The patient was subsequently treated with toripalimab monotherapy for six cycles, achieving complete tumor regression and a clinical complete response. This was followed by four cycles of consolidation immunotherapy. At the most recent follow-up, the patient remained disease-free. Conclusion: This case highlights the diagnostic challenges and aggressive clinical behavior of undifferentiated cervical sarcoma and suggests a potential role for immune checkpoint inhibition in PD-L1-positive recurrent disease. Further studies are needed to confirm the findings.