Primary Vulvar Leiomyosarcoma Presenting as a Cyst Like Mass in a Middle Aged Woman: A Case Report

Background: Vulvar leiomyosarcoma (VLMS) is the commonest vulvar sarcoma yet represents <1?% of all vulvar malignancies, making evidence based management challenging. Its ability to masquerade as benign Bartholin?gland cysts or leiomyomas frequently delays definitive treatment. Case Report: We report a 46 year old multiparous woman who presented with a slowly growing, painless swelling of the left vulvo vaginal vestibule. Baseline laboratory evaluation revealed mild normocytic anaemia with normal biochemical investigations. Pelvic ultrasonography demonstrated a well circumscribed hypoechoic mass measuring 5.8???4.2???3.0?cm separated from Bartholin?s gland. The lesion was excised with 1 cm macroscopic margins. Grossly the tumour was tan white, solid and whorled. Histology disclosed a cellular tumor composed of intersecting fascicles of spindle cells with moderate to marked nuclear pleomorphism and brisk mitotic activity (12/10?HPF). Immunohistochemistry was strongly positive for SMA and desmin and negative for S 100, CD34 confirming leiomyosarcoma. Surgical margins were histologically free. Adjuvant radiotherapy was deferred after multidisciplinary review because of clear margins and low to intermediate grade. The patient remains disease free at 9?months. Conclusion: Early complete excision with free surgical margins and histological confirmation is paramount in VLMS because clinical and radiological findings may mimic benign disease. Close surveillance is essential in view of documented late recurrences. This case adds to the limited pool of VLMS reports and highlights contemporary diagnostic and therapeutic considerations.