Vaginal malignant peripheral nerve sheath tumor treated with complete surgical resection and postoperative radiation therapy.

Malignant peripheral nerve sheath tumors (MPNSTs) are neoplasms originating from or differentiating into nerve sheaths of peripheral nerves. Vaginal origin is rare, with only six vaginal primary cases reported to date. A 55-year-old woman presented to our hospital with a 7 cm vulvar mass. Tumor biopsy results were suspicious of sarcoma, and pelvic magnetic resonance imaging and hysterofiberscopy showed that the tumor originated from the lower vagina. The mass was transvaginally excised, and histological examination confirmed the diagnosis of a vaginal MPNST with negative surgical margins. The patient underwent radiotherapy because the risk of recurrence was high, owing to the large tumor size and high mitotic index. The patient remained recurrence-free for 1 year after the primary treatment. This is the first case of a high-risk vaginal MPNST that avoided early disease recurrence with additional radiotherapy after complete tumor resection.