Late Recurrence of High-Grade Vulvar Leiomyosarcoma After 5 Years: A Rare Case Report and Expanded Review of Reported Cases

<b>Background:</b> Vulvar leiomyosarcoma (VLMS) is a rare and aggressive soft tissue malignancy arising from smooth muscle cells, comprising less than 3% of vulvar cancers. Its clinical resemblance to benign vulvar lesions often leads to delayed diagnosis. Despite surgical resection and adjuvant therapy, VLMS is associated with high recurrence rates and a poor prognosis, and due to its rarity, there is no standardized management or surveillance protocol. <b>Case Report:</b> We present a case of high-grade VLMS in a postmenopausal woman, initially diagnosed in 2020 and managed with surgical excision and adjuvant radiotherapy. The primary tumor was a 10 cm solid, lobulated mass involving the mons pubis, with histology confirming high-grade leiomyosarcoma based on marked cellular atypia, high mitotic activity, and smooth muscle differentiation. Immunohistochemistry was positive for SMA, vimentin, and CD34, and negative for S100 and MyoD1. Five years later, the patient developed a local recurrence with an enlarged inguinal lymph node. She underwent complete tumor resection and bilateral inguinal lymphadenectomy. Histology of the recurrent lesion mirrored the initial findings, with no lymph node metastases. This case highlights the aggressive nature and potential for late recurrence in vulvar leiomyosarcoma, underscoring the importance of long-term surveillance. <b>Conclusions:</b> High-grade VLMS is a rare malignancy with a high recurrence risk. This case highlights the importance of early diagnosis, radical surgical treatment, and long-term surveillance. Although recurrence occurred five years after the initial treatment, timely surgical intervention led to a favorable postoperative course. Multidisciplinary management and individualized follow-up strategies remain key to improving outcomes in these rare gynecologic sarcomas.