Primary Vaginal Leiomyosarcoma: A Systematic Review and Institutional Case of the Myxoid Variant

Objective Vaginal leiomyosarcoma is an extremely rare malignant tumour, representing less than 1% of all vaginal sarcoma. Given the absence of standardised treatment protocols and the limited evidence available, we report a systematic review of the literature providing a comprehensive overview. Methods A systematic review was conducted across multiple databases and updated through 13 August 2026 and reported in accordance with the PRISMA guidelines (PROSPERO: CRD420261385832). All study designs reporting at least one histologically confirmed case of vaginal leiomyosarcoma were eligible. Survival outcomes were assessed using the Kaplan–Meier method with exploratory subgroup analyses according to relevant clinicopathological characteristics. A separate institutional case of primary myxoid vaginal leiomyosarcoma is presented and was excluded from the systematic review cohort and analyses. Results Sixty-one studies comprising 108 histologically confirmed cases of vaginal leiomyosarcoma were identified. Symptoms were vague and nonspecific. Local excision was the most frequently performed procedure (73.2%). Adjuvant therapy was heterogeneous: 46.2% of patients received no adjuvant treatment, while radiotherapy and chemotherapy were administered in 37.2% and 25.6% of cases, respectively. Recurrence was documented in 39.3% of patients. At last follow-up, 53.9% were alive with no evidence of disease and 43.8% had died of disease. Median disease-free survival was 26 months, and median disease-specific survival was 41 months, with 5-year rates of 31.1% and 40.5%, respectively. Exploratory analyses showed that disease-specific survival differed according to FIGO stage and tumour grade, while disease-free survival differed according to tumour grade. The myxoid variant was illustrated by documented occurrence of primary myxoid vaginal leiomyosarcoma, where preoperative biopsy suggested a benign smooth muscle proliferation, whereas final histology established the diagnosis of myxoid leiomyosarcoma. Conclusions Primary vaginal leiomyosarcoma is a rare malignancy characterised by heterogeneous management, frequent recurrence, and unfavourable survival outcomes. International multicentre registries are needed to generate evidence-based guidelines for this rare malignancy.