Primary Vulvar Leiomyosarcoma Presenting As A Cyst Like Mass In A 46 Year Old Woman: A Case Report And Review Of The Literature

Abstract

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: We describe a 46 year old multiparous woman who presented with a slowly enlarging, painful swelling of the left vulvo vaginal vestibule. Baseline laboratory evaluation revealed mild normocytic anaemia (Hb 11.5 g/dL) with an ESR of 62 mm 1st h but otherwise normal liver, renal and coagulation profiles. Pelvic ultrasonography demonstrated a well circumscribed hypoechoic mass measuring 5.8 × 4.2 × 3.0 cm separate from Bartholin’s gland. The lesion was excised with 1 cm macroscopic margins. Grossly the tumour was tan white, whorled and partly cystic. Histology disclosed intersecting fascicles of spindle cells with moderate to marked nuclear pleomorphism, brisk mitotic activity (12/10 HPF) and focal necrosis. Immunohistochemistry was strongly positive for SMA and desmin and negative for S 100, confirming grade 2 leiomyosarcoma. Surgical margins were histologically free. Adjuvant radiotherapy was deferred after multidisciplinary review because of clear margins and low intermediate grade. The patient remains disease free at 9 months. Conclusion: Early complete excision with 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.