Case of pulmonary benign metastasizing leiomyoma from synchronous uterine leiomyoma in a postmenopausal woman

Benign metastasizing leiomyoma (BML) is a rare tumor comprising histologically benign smooth muscle cells and exhibits the same histological findings as a uterine myoma although in an extra-uterine location. Most BMLs occur several years after surgery for uterine myoma in women of reproductive age. Here, we report a case of pulmonary BML in a 54-year-old postmenopausal woman with no previous history of myomectomy or hysterectomy. The patient presented with a rapid increase in abdominal girth over the past 3 months and a cough lasting for 2 months. Chest computed tomography (CT) revealed multiple pulmonary nodules, ranging in diameter from a few millimeters to 1.5 cm. Abdominal CT revealed a well-defined heterogeneous hypervascular uterine mass measuring 25 cm at the widest diameter. In addition to the uterine mass, imaging studies identified no other origin of the metastatic lung nodules. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed followed by video-assisted thoracoscopy. The histological findings of the lungs and uterus suggested myoma. The patient remains asymptomatic and disease-free at 7 years after surgery without adjuvant treatment.