Benign metastasizing leiomyoma of the lung: A case report and literature review.

Pulmonary benign metastasizing leiomyoma (BML) is a rare event characterized by benign soft-tissue tumors that occur when uterine leiomyomas metastasize to the lung. The present study reports the case of a 47-year-old female patient who presented with multiple bilateral pulmonary nodules on a chest X-ray during a health checkup nine years after a hysterectomy due to uterine fibroids. Chest computed tomography (CT) revealed multiple well-defined nodular shadows in the lung. One tumor of the left upper lung was resected by thoracoscopic surgery. Pathologically, the resected lesion consisted of benign spindle cells and was diagnosed as BML. The post-operative course was uneventful. Other lung nodules have been meticulously monitored at follow-up, and repeat CT two years later showed that these nodules had not increased at all in size and that no new lobe nodules had appeared. The present study indicates that pulmonary BML occurs in a low proportion of female with a history of uterine leiomyoma and treatment methods for it are diverse and controversial.