Pulmonary Benign Metastasizing Leiomyoma in a Postmenopausal Woman

Pulmonary benign metastasizing leiomyoma (BML) is a rare disease occurring predominantly in women of reproductive age and usually develops several years after the resection of a uterine leiomyoma. A 52-year-old postmenopausal woman was admitted to our hospital because of a right-sided empyema. Contrast-enhanced computed tomography showed a multiloculated pleural effusion on the right side and multiple small nodules in the left lung. A wedge biopsy revealed the pulmonary nodule consisting of branching glandular structures surrounded by abundant smooth muscle cells with no atypia. We performed a gynecologic examination to identify the primary origin of the pulmonary smooth muscle tumors. A uterine leiomyoma was found, and the patient underwent a total hysterectomy. Both pulmonary nodules and uterine leiomyoma were positive for estrogen and progesterone receptors. Therefore, we diagnosed the pulmonary lesions as BMLs. This is an interesting case of pulmonary BML identified simultaneously with uterine myoma in a postmenopausal woman. BML should be considered in women with multiple pulmonary nodules, even though it is rare.