Abstract
BACKGROUND: Primary ovarian leiomyosarcoma is an exceedingly rare and aggressive tumor, accounting for less than 0.1% of ovarian malignancies. Owing to its nonspecific clinical presentation, primary ovarian leiomyosarcoma is often diagnosed at an advanced stage. To date, metastatic spread to the gallbladder has not been documented. CASE PRESENTATION: We present the first reported case of gallbladder metastasis arising from stage IVB primary ovarian leiomyosarcoma. A 55-year-old Iranian woman initially presented with a large ovarian mass and bilateral pulmonary metastases. She underwent radical surgical management-including total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and pelvic lymphadenectomy-followed by adjuvant chemotherapy with ifosfamide and doxorubicin. Owing to persistent pulmonary lesions, her regimen was switched to gemcitabine-docetaxel, which led to a partial response. During follow-up, imaging unexpectedly revealed gallbladder lesions, which were confirmed as metastatic primary ovarian leiomyosarcoma via laparoscopic cholecystectomy and histopathological analysis. Despite further systemic therapies, including sunitinib and a return to gemcitabine-docetaxel, the disease progressed with additional metastases to the liver, spine, and pancreas. The patient died 49 months after the initial surgery. CONCLUSION: This case highlights an unprecedented metastatic pattern in primary ovarian leiomyosarcoma and suggests that individualized, multidisciplinary care may offer meaningful benefit in advanced disease. Given the rarity of primary ovarian leiomyosarcoma, cautious interpretation is warranted, and standardized treatment guidelines remain urgently needed. Vigilant long-term follow-up is crucial for detecting atypical disease progression.