To explore the clinical manifestations, diagnosis, and treatment of recurrent endometriosis (EMS) that has undergone malignant transformation into vaginal stump adenosarcoma.

A patient with vaginal stump adenosarcoma arising from recurrent EMS, who was treated at West China Second University Hospital, Sichuan University, in December 2024 (patient 1), was selected into this study. A retrospective analysis of the patient′s clinical records was conducted, including medical history, clinical presentation, imaging findings, pathological characteristics, treatment, and follow-up results. Using Chinese and English keywords such as " adenosarcoma" " vaginal stump" and " endometriosis", we searched the CNKI, Wanfang, and VIP databases, as well as PubMed and Web of Science (WoS), for relevant literature on the malignant transformation of endometriosis into vaginal stump adenosarcoma, and conducted a comprehensive analysis of the medical history, clinical manifestations, imaging findings, pathological characteristics, treatment, and follow-up outcomes of these patients. The procedures followed in this study complied with the standards set by the Ethics Committee of West China Second University Hospital, Sichuan University, and were approved by the Ethics Committee [Approval No.2025(315)].

① Patient 1, a 51-year-old woman (G₃P₁), presented to the Gynecology Department of our hospital on December 18, 2024, with a chief complaint of " a mass at the vaginal stump discovered over a year ago". Patient 1 has a history of EMS and was admitted to our hospital due to a gradually enlarging mass at the vaginal stump accompanied by vaginal bleeding. A pelvic MRI performed prior to admission revealed multiple nodular and mass-like lesions in the vaginal stump and the left pelvis. Elevated levels of carbohydrate antigens (CA) 125 and CA19-9 were observed; however, a needle biopsy of the vaginal stump lesion did not reveal any definitive evidence of malignancy. Following admission, the patient underwent resection of the vaginal stump lesion by laparotomy. Postoperative pathological examination confirmed that the polypoid EMS had undergone malignant transformation into adenosarcoma, with the sarcomatous component consisting of endometrial stromal sarcoma and rhabdomyosarcoma. Postoperatively, the patient received pelvic external beam radiation therapy combined with six cycles of chemotherapy. Seven months after the last cycle of chemotherapy, no residual tumor or recurrence was observed. ②Literature review results: Using the literature search strategy established in this study, a total of 7 research articles related to the malignant transformation of EMS into vaginal stump adenosarcoma were identified. Including patient 1, a total of 8 relevant patients were included in the study. A comprehensive analysis of their medical histories, clinical presentations, imaging findings, pathological characteristics, treatment, and follow-up results is presented below.The median age of these 8 patients was 48.5 years old. The primary clinical manifestation was vaginal bleeding (patients 1-3, and 5); pelvic masses were present in 3 cases (patients 6-8); and urinary incontinence and vaginal mass prolapse were present in 1 case (patient 4). In addition, three cases (patients 1, 5, and 8) exhibited heterotopic differentiation of the sarcomatous component, and two cases (patients 2 and 3) showed overgrowth of the sarcomatous component. All 8 patients underwent surgical treatment. One patient (patient 2) died following a recurrence; 3 patients (patients 5, 6, and 8) achieved remission following treatment after recurrence; and the remaining 4 patients (patients 1, 3, 4, and 7) did not experience recurrence during the follow-up period after their initial treatment.

Vaginal stump adenosarcoma arising from the malignant transformation of EMS is a relatively rare clinical condition, and lacks specific clinical and imaging features. Definitive diagnosis mainly relies on histopathological examination. Surgical resection remains the primary treatment, and the decision to administer adjuvant radiation therapy and/or chemotherapy after surgery should be made based on a comprehensive assessment of pathological characteristics and individual patient circumstances.